
Introduction
In mathematics, finding the best fit function for a given dataset is a crucial task in various fields such as statistics, engineering, and data analysis. A quartic function is a polynomial function of degree four, which means it has the general form of f(x)=ax4+bx3+cx2+dx+e. In this article, we will discuss how to find the quartic function that best fits the data in the given table.
Understanding the Data
The given table contains seven data points, each with a corresponding value of x and y. The data points are:
x |
y |
-3 |
70 |
-2 |
15 |
-1 |
4 |
0 |
1 |
1 |
-6 |
2 |
-5 |
3 |
40 |
The Method of Least Squares
The method of least squares is a widely used technique for finding the best fit function for a given dataset. The basic idea behind this method is to minimize the sum of the squared errors between the observed data points and the predicted values of the function.
Let's assume that we have a function f(x)=ax4+bx3+cx2+dx+e that we want to fit to the given data. We can write the sum of the squared errors as:
S=i=1∑n​(yi​−f(xi​))2
where yi​ is the observed value of the ith data point, f(xi​) is the predicted value of the function at xi​, and n is the number of data points.
Finding the Coefficients of the Quartic Function
To find the coefficients of the quartic function, we need to minimize the sum of the squared errors S. This can be done by taking the partial derivatives of S with respect to each of the coefficients a, b, c, d, and e, and setting them equal to zero.
Let's denote the partial derivatives of S with respect to each of the coefficients as:
∂a∂S​=0
∂b∂S​=0
∂c∂S​=0
∂d∂S​=0
∂e∂S​=0
Solving these equations simultaneously will give us the values of the coefficients a, b, c, d, and e that minimize the sum of the squared errors.
Calculating the Coefficients
To calculate the coefficients, we need to use the given data points and the equations of the partial derivatives. Let's denote the given data points as:
xi​ |
yi​ |
-3 |
70 |
-2 |
15 |
-1 |
4 |
0 |
1 |
1 |
-6 |
2 |
-5 |
3 |
40 |
Using the equations of the partial derivatives, we can calculate the coefficients as follows:
a=∑i=1n​xi8​−n(∑i=1n​xi4​)2​∑i=1n​yi​xi4​−n∑i=1n​xi4​∑i=1n​yi​​​
b=∑i=1n​xi6​−n(∑i=1n​xi3​)2​∑i=1n​yi​xi3​−n∑i=1n​xi3​∑i=1n​yi​​​
c=∑i=1n​xi4​−n(∑i=1n​xi2​)2​∑i=1n​yi​xi2​−n∑i=1n​xi2​∑i=1n​yi​​​
d=∑i=1n​xi2​−n(∑i=1n​xi​)2​∑i=1n​yi​xi​−n∑i=1n​xi​∑i=1n​yi​​​
e=∑i=1n​1−n(∑i=1n​1)2​∑i=1n​yi​−n∑i=1n​∑i=1n​yi​​​
Calculating the Coefficients Values
Using the given data points, we can calculate the values of the coefficients as follows:
a=7(−3)8+(−2)8+(−1)8+08+18+28+38​−7((−3)4+(−2)4+(−1)4+04+14+24+34)2​70(−3)4+15(−2)4+4(−1)4+1(0)4−6(1)4−5(2)4+40(3)4−770(−3)4+15(−2)4+4(−1)4+1(0)4−6(1)4−5(2)4+40(3)4​​
b=7(−3)6+(−2)6+(−1)6+06+16+26+36​−7((−3)3+(−2)3+(−1)3+03+13+23+33)2​70(−3)3+15(−2)3+4(−1)3+1(0)3−6(1)3−5(2)3+40(3)3−770(−3)3+15(−2)3+4(−1)3+1(0)3−6(1)3−5(2)3+40(3)3​​
c=7(−3)4+(−2)4+(−1)4+04+14+24+34​−7((−3)2+(−2)2+(−1)2+02+12+22+32)2​70(−3)2+15(−2)2+4(−1)2+1(0)2−6(1)2−5(2)2+40(3)2−770(−3)2+15(−2)2+4(−1)2+1(0)2−6(1)2−5(2)2+40(3)2​​
d=7(−3)2+(−2)2+(−1)2+02+12+22+32​−7((−3)+(−2)+(−1)+0+1+2+3)2​70(−3)+15(−2)+4(−1)+1(0)−6(1)−5(2)+40(3)−770(−3)+15(−2)+4(−1)+1(0)−6(1)−5(2)+40(3)​​
e = \frac{70 + 15 + 4 + 1 - 6 - 5 + 40 - \frac{70 + 15 + 4 + 1 - 6 - 5 + 40}{7}}{\frac{1 + 1 + 1 + 1 + 1 + 1 + 1}{7} - \<br/>
**Q&A: Finding the Best Fit Quartic Function for Given Data**
===========================================================
Q: What is the method of least squares?

A: The method of least squares is a widely used technique for finding the best fit function for a given dataset. The basic idea behind this method is to minimize the sum of the squared errors between the observed data points and the predicted values of the function.
Q: How do I calculate the coefficients of the quartic function using the method of least squares?
A: To calculate the coefficients of the quartic function, you need to use the given data points and the equations of the partial derivatives. The equations are:
a=∑i=1n​xi8​−n(∑i=1n​xi4​)2​∑i=1n​yi​xi4​−n∑i=1n​xi4​∑i=1n​yi​​​</span></p><pclass=′katex−block′><spanclass="katex−display"><spanclass="katex"><spanclass="katex−mathml"><mathxmlns="http://www.w3.org/1998/Math/MathML"display="block"><semantics><mrow><mi>b</mi><mo>=</mo><mfrac><mrow><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msub><mi>y</mi><mi>i</mi></msub><msubsup><mi>x</mi><mi>i</mi><mn>3</mn></msubsup><mo>−</mo><mfrac><mrow><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msubsup><mi>x</mi><mi>i</mi><mn>3</mn></msubsup><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msub><mi>y</mi><mi>i</mi></msub></mrow><mi>n</mi></mfrac></mrow><mrow><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msubsup><mi>x</mi><mi>i</mi><mn>6</mn></msubsup><mo>−</mo><mfrac><mrow><mostretchy="false">(</mo><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msubsup><mi>x</mi><mi>i</mi><mn>3</mn></msubsup><msup><mostretchy="false">)</mo><mn>2</mn></msup></mrow><mi>n</mi></mfrac></mrow></mfrac></mrow><annotationencoding="application/x−tex">b=∑i=1n​xi6​−n(∑i=1n​xi3​)2​∑i=1n​yi​xi3​−n∑i=1n​xi3​∑i=1n​yi​​​</annotation></semantics></math></span><spanclass="katex−html"aria−hidden="true"><spanclass="base"><spanclass="strut"style="height:0.6944em;"></span><spanclass="mordmathnormal">b</span><spanclass="mspace"style="margin−right:0.2778em;"></span><spanclass="mrel">=</span><spanclass="mspace"style="margin−right:0.2778em;"></span></span><spanclass="base"><spanclass="strut"style="height:3.2281em;vertical−align:−1.3342em;"></span><spanclass="mord"><spanclass="mopennulldelimiter"></span><spanclass="mfrac"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:1.8939em;"><spanstyle="top:−2.1697em;"><spanclass="pstrut"style="height:3.1589em;"></span><spanclass="mord"><spanclass="mop"><spanclass="mopop−symbolsmall−op"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8043em;"><spanstyle="top:−2.4003em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−3.2029em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2997em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.1667em;"></span><spanclass="mord"><spanclass="mordmathnormal">x</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7959em;"><spanstyle="top:−2.4231em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmathnormalmtight">i</span></span></span><spanstyle="top:−3.0448em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight">6</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2769em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mbin">−</span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mord"><spanclass="mopennulldelimiter"></span><spanclass="mfrac"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:1.0992em;"><spanstyle="top:−2.655em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span><spanstyle="top:−3.23em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="frac−line"style="border−bottom−width:0.04em;"></span></span><spanstyle="top:−3.5356em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mopenmtight">(</span><spanclass="mopmtight"><spanclass="mopop−symbolsmall−opmtight"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7047em;"><spanstyle="top:−2.1786em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−2.8971em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3214em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mordmtight"><spanclass="mordmathnormalmtight">x</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8051em;"><spanstyle="top:−2.1777em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmathnormalmtight">i</span></span></span><spanstyle="top:−2.8448em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight">3</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3223em;"><span></span></span></span></span></span></span><spanclass="mclosemtight"><spanclass="mclosemtight">)</span><spanclass="msupsub"><spanclass="vlist−t"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7463em;"><spanstyle="top:−2.786em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight">2</span></span></span></span></span></span></span></span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.345em;"><span></span></span></span></span></span><spanclass="mclosenulldelimiter"></span></span></span></span><spanstyle="top:−3.3889em;"><spanclass="pstrut"style="height:3.1589em;"></span><spanclass="frac−line"style="border−bottom−width:0.04em;"></span></span><spanstyle="top:−3.8939em;"><spanclass="pstrut"style="height:3.1589em;"></span><spanclass="mord"><spanclass="mop"><spanclass="mopop−symbolsmall−op"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8043em;"><spanstyle="top:−2.4003em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−3.2029em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2997em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.1667em;"></span><spanclass="mord"><spanclass="mordmathnormal"style="margin−right:0.03588em;">y</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.3117em;"><spanstyle="top:−2.55em;margin−left:−0.0359em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmathnormalmtight">i</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.15em;"><span></span></span></span></span></span></span><spanclass="mord"><spanclass="mordmathnormal">x</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8141em;"><spanstyle="top:−2.4413em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmathnormalmtight">i</span></span></span><spanstyle="top:−3.063em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight">3</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2587em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mbin">−</span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mord"><spanclass="mopennulldelimiter"></span><spanclass="mfrac"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:1.1589em;"><spanstyle="top:−2.655em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span><spanstyle="top:−3.23em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="frac−line"style="border−bottom−width:0.04em;"></span></span><spanstyle="top:−3.535em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mopmtight"><spanclass="mopop−symbolsmall−opmtight"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7385em;"><spanstyle="top:−2.1786em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−2.931em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3214em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mordmtight"><spanclass="mordmathnormalmtight">x</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8913em;"><spanstyle="top:−2.214em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmathnormalmtight">i</span></span></span><spanstyle="top:−2.931em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight">3</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.286em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mopmtight"><spanclass="mopop−symbolsmall−opmtight"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7385em;"><spanstyle="top:−2.1786em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−2.931em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3214em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mordmtight"><spanclass="mordmathnormalmtight"style="margin−right:0.03588em;">y</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.3281em;"><spanstyle="top:−2.357em;margin−left:−0.0359em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmathnormalmtight">i</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.345em;"><span></span></span></span></span></span><spanclass="mclosenulldelimiter"></span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:1.3342em;"><span></span></span></span></span></span><spanclass="mclosenulldelimiter"></span></span></span></span></span></span></p><pclass=′katex−block′><spanclass="katex−display"><spanclass="katex"><spanclass="katex−mathml"><mathxmlns="http://www.w3.org/1998/Math/MathML"display="block"><semantics><mrow><mi>c</mi><mo>=</mo><mfrac><mrow><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msub><mi>y</mi><mi>i</mi></msub><msubsup><mi>x</mi><mi>i</mi><mn>2</mn></msubsup><mo>−</mo><mfrac><mrow><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msubsup><mi>x</mi><mi>i</mi><mn>2</mn></msubsup><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msub><mi>y</mi><mi>i</mi></msub></mrow><mi>n</mi></mfrac></mrow><mrow><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msubsup><mi>x</mi><mi>i</mi><mn>4</mn></msubsup><mo>−</mo><mfrac><mrow><mostretchy="false">(</mo><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msubsup><mi>x</mi><mi>i</mi><mn>2</mn></msubsup><msup><mostretchy="false">)</mo><mn>2</mn></msup></mrow><mi>n</mi></mfrac></mrow></mfrac></mrow><annotationencoding="application/x−tex">c=∑i=1n​xi4​−n(∑i=1n​xi2​)2​∑i=1n​yi​xi2​−n∑i=1n​xi2​∑i=1n​yi​​​</annotation></semantics></math></span><spanclass="katex−html"aria−hidden="true"><spanclass="base"><spanclass="strut"style="height:0.4306em;"></span><spanclass="mordmathnormal">c</span><spanclass="mspace"style="margin−right:0.2778em;"></span><spanclass="mrel">=</span><spanclass="mspace"style="margin−right:0.2778em;"></span></span><spanclass="base"><spanclass="strut"style="height:3.2281em;vertical−align:−1.3342em;"></span><spanclass="mord"><spanclass="mopennulldelimiter"></span><spanclass="mfrac"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:1.8939em;"><spanstyle="top:−2.1697em;"><spanclass="pstrut"style="height:3.1589em;"></span><spanclass="mord"><spanclass="mop"><spanclass="mopop−symbolsmall−op"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8043em;"><spanstyle="top:−2.4003em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−3.2029em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2997em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.1667em;"></span><spanclass="mord"><spanclass="mordmathnormal">x</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7959em;"><spanstyle="top:−2.4231em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmathnormalmtight">i</span></span></span><spanstyle="top:−3.0448em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight">4</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2769em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mbin">−</span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mord"><spanclass="mopennulldelimiter"></span><spanclass="mfrac"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:1.0992em;"><spanstyle="top:−2.655em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span><spanstyle="top:−3.23em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="frac−line"style="border−bottom−width:0.04em;"></span></span><spanstyle="top:−3.5356em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mopenmtight">(</span><spanclass="mopmtight"><spanclass="mopop−symbolsmall−opmtight"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7047em;"><spanstyle="top:−2.1786em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−2.8971em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3214em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mordmtight"><spanclass="mordmathnormalmtight">x</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8051em;"><spanstyle="top:−2.1777em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmathnormalmtight">i</span></span></span><spanstyle="top:−2.8448em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight">2</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3223em;"><span></span></span></span></span></span></span><spanclass="mclosemtight"><spanclass="mclosemtight">)</span><spanclass="msupsub"><spanclass="vlist−t"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7463em;"><spanstyle="top:−2.786em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight">2</span></span></span></span></span></span></span></span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.345em;"><span></span></span></span></span></span><spanclass="mclosenulldelimiter"></span></span></span></span><spanstyle="top:−3.3889em;"><spanclass="pstrut"style="height:3.1589em;"></span><spanclass="frac−line"style="border−bottom−width:0.04em;"></span></span><spanstyle="top:−3.8939em;"><spanclass="pstrut"style="height:3.1589em;"></span><spanclass="mord"><spanclass="mop"><spanclass="mopop−symbolsmall−op"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8043em;"><spanstyle="top:−2.4003em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−3.2029em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2997em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.1667em;"></span><spanclass="mord"><spanclass="mordmathnormal"style="margin−right:0.03588em;">y</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.3117em;"><spanstyle="top:−2.55em;margin−left:−0.0359em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmathnormalmtight">i</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.15em;"><span></span></span></span></span></span></span><spanclass="mord"><spanclass="mordmathnormal">x</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8141em;"><spanstyle="top:−2.4413em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmathnormalmtight">i</span></span></span><spanstyle="top:−3.063em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight">2</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2587em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mbin">−</span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mord"><spanclass="mopennulldelimiter"></span><spanclass="mfrac"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:1.1589em;"><spanstyle="top:−2.655em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span><spanstyle="top:−3.23em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="frac−line"style="border−bottom−width:0.04em;"></span></span><spanstyle="top:−3.535em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mopmtight"><spanclass="mopop−symbolsmall−opmtight"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7385em;"><spanstyle="top:−2.1786em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−2.931em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3214em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mordmtight"><spanclass="mordmathnormalmtight">x</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8913em;"><spanstyle="top:−2.214em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmathnormalmtight">i</span></span></span><spanstyle="top:−2.931em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight">2</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.286em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mopmtight"><spanclass="mopop−symbolsmall−opmtight"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7385em;"><spanstyle="top:−2.1786em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−2.931em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3214em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mordmtight"><spanclass="mordmathnormalmtight"style="margin−right:0.03588em;">y</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.3281em;"><spanstyle="top:−2.357em;margin−left:−0.0359em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmathnormalmtight">i</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.345em;"><span></span></span></span></span></span><spanclass="mclosenulldelimiter"></span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:1.3342em;"><span></span></span></span></span></span><spanclass="mclosenulldelimiter"></span></span></span></span></span></span></p><pclass=′katex−block′><spanclass="katex−display"><spanclass="katex"><spanclass="katex−mathml"><mathxmlns="http://www.w3.org/1998/Math/MathML"display="block"><semantics><mrow><mi>d</mi><mo>=</mo><mfrac><mrow><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msub><mi>y</mi><mi>i</mi></msub><msub><mi>x</mi><mi>i</mi></msub><mo>−</mo><mfrac><mrow><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msub><mi>x</mi><mi>i</mi></msub><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msub><mi>y</mi><mi>i</mi></msub></mrow><mi>n</mi></mfrac></mrow><mrow><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msubsup><mi>x</mi><mi>i</mi><mn>2</mn></msubsup><mo>−</mo><mfrac><mrow><mostretchy="false">(</mo><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msub><mi>x</mi><mi>i</mi></msub><msup><mostretchy="false">)</mo><mn>2</mn></msup></mrow><mi>n</mi></mfrac></mrow></mfrac></mrow><annotationencoding="application/x−tex">d=∑i=1n​xi2​−n(∑i=1n​xi​)2​∑i=1n​yi​xi​−n∑i=1n​xi​∑i=1n​yi​​​</annotation></semantics></math></span><spanclass="katex−html"aria−hidden="true"><spanclass="base"><spanclass="strut"style="height:0.6944em;"></span><spanclass="mordmathnormal">d</span><spanclass="mspace"style="margin−right:0.2778em;"></span><spanclass="mrel">=</span><spanclass="mspace"style="margin−right:0.2778em;"></span></span><spanclass="base"><spanclass="strut"style="height:3.09em;vertical−align:−1.295em;"></span><spanclass="mord"><spanclass="mopennulldelimiter"></span><spanclass="mfrac"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:1.795em;"><spanstyle="top:−2.11em;"><spanclass="pstrut"style="height:3.06em;"></span><spanclass="mord"><spanclass="mop"><spanclass="mopop−symbolsmall−op"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8043em;"><spanstyle="top:−2.4003em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−3.2029em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2997em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.1667em;"></span><spanclass="mord"><spanclass="mordmathnormal">x</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7959em;"><spanstyle="top:−2.4231em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmathnormalmtight">i</span></span></span><spanstyle="top:−3.0448em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight">2</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2769em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mbin">−</span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mord"><spanclass="mopennulldelimiter"></span><spanclass="mfrac"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:1.06em;"><spanstyle="top:−2.655em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span><spanstyle="top:−3.23em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="frac−line"style="border−bottom−width:0.04em;"></span></span><spanstyle="top:−3.535em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mopenmtight">(</span><spanclass="mopmtight"><spanclass="mopop−symbolsmall−opmtight"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7047em;"><spanstyle="top:−2.1786em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−2.8971em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3214em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mordmtight"><spanclass="mordmathnormalmtight">x</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.3281em;"><spanstyle="top:−2.357em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmathnormalmtight">i</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.143em;"><span></span></span></span></span></span></span><spanclass="mclosemtight"><spanclass="mclosemtight">)</span><spanclass="msupsub"><spanclass="vlist−t"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7463em;"><spanstyle="top:−2.786em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight">2</span></span></span></span></span></span></span></span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.345em;"><span></span></span></span></span></span><spanclass="mclosenulldelimiter"></span></span></span></span><spanstyle="top:−3.29em;"><spanclass="pstrut"style="height:3.06em;"></span><spanclass="frac−line"style="border−bottom−width:0.04em;"></span></span><spanstyle="top:−3.795em;"><spanclass="pstrut"style="height:3.06em;"></span><spanclass="mord"><spanclass="mop"><spanclass="mopop−symbolsmall−op"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8043em;"><spanstyle="top:−2.4003em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−3.2029em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2997em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.1667em;"></span><spanclass="mord"><spanclass="mordmathnormal"style="margin−right:0.03588em;">y</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.3117em;"><spanstyle="top:−2.55em;margin−left:−0.0359em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmathnormalmtight">i</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.15em;"><span></span></span></span></span></span></span><spanclass="mord"><spanclass="mordmathnormal">x</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.3117em;"><spanstyle="top:−2.55em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmathnormalmtight">i</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.15em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mbin">−</span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mord"><spanclass="mopennulldelimiter"></span><spanclass="mfrac"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:1.06em;"><spanstyle="top:−2.655em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span><spanstyle="top:−3.23em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="frac−line"style="border−bottom−width:0.04em;"></span></span><spanstyle="top:−3.535em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mopmtight"><spanclass="mopop−symbolsmall−opmtight"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7385em;"><spanstyle="top:−2.1786em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−2.931em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3214em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mordmtight"><spanclass="mordmathnormalmtight">x</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.3281em;"><spanstyle="top:−2.357em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmathnormalmtight">i</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.143em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mopmtight"><spanclass="mopop−symbolsmall−opmtight"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7385em;"><spanstyle="top:−2.1786em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−2.931em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3214em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mordmtight"><spanclass="mordmathnormalmtight"style="margin−right:0.03588em;">y</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.3281em;"><spanstyle="top:−2.357em;margin−left:−0.0359em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmathnormalmtight">i</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.345em;"><span></span></span></span></span></span><spanclass="mclosenulldelimiter"></span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:1.295em;"><span></span></span></span></span></span><spanclass="mclosenulldelimiter"></span></span></span></span></span></span></p><pclass=′katex−block′><spanclass="katex−display"><spanclass="katex"><spanclass="katex−mathml"><mathxmlns="http://www.w3.org/1998/Math/MathML"display="block"><semantics><mrow><mi>e</mi><mo>=</mo><mfrac><mrow><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msub><mi>y</mi><mi>i</mi></msub><mo>−</mo><mfrac><mrow><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><msub><mi>y</mi><mi>i</mi></msub></mrow><mi>n</mi></mfrac></mrow><mrow><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><mn>1</mn><mo>−</mo><mfrac><mrow><mostretchy="false">(</mo><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow><mi>n</mi></munderover><mn>1</mn><msup><mostretchy="false">)</mo><mn>2</mn></msup></mrow><mi>n</mi></mfrac></mrow></mfrac></mrow><annotationencoding="application/x−tex">e=∑i=1n​1−n(∑i=1n​1)2​∑i=1n​yi​−n∑i=1n​∑i=1n​yi​​​</annotation></semantics></math></span><spanclass="katex−html"aria−hidden="true"><spanclass="base"><spanclass="strut"style="height:0.4306em;"></span><spanclass="mordmathnormal">e</span><spanclass="mspace"style="margin−right:0.2778em;"></span><spanclass="mrel">=</span><spanclass="mspace"style="margin−right:0.2778em;"></span></span><spanclass="base"><spanclass="strut"style="height:3.09em;vertical−align:−1.295em;"></span><spanclass="mord"><spanclass="mopennulldelimiter"></span><spanclass="mfrac"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:1.795em;"><spanstyle="top:−2.11em;"><spanclass="pstrut"style="height:3.06em;"></span><spanclass="mord"><spanclass="mop"><spanclass="mopop−symbolsmall−op"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8043em;"><spanstyle="top:−2.4003em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−3.2029em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2997em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.1667em;"></span><spanclass="mord">1</span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mbin">−</span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mord"><spanclass="mopennulldelimiter"></span><spanclass="mfrac"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:1.06em;"><spanstyle="top:−2.655em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span><spanstyle="top:−3.23em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="frac−line"style="border−bottom−width:0.04em;"></span></span><spanstyle="top:−3.535em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mopenmtight">(</span><spanclass="mopmtight"><spanclass="mopop−symbolsmall−opmtight"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7047em;"><spanstyle="top:−2.1786em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−2.8971em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3214em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mordmtight">1</span><spanclass="mclosemtight"><spanclass="mclosemtight">)</span><spanclass="msupsub"><spanclass="vlist−t"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7463em;"><spanstyle="top:−2.786em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight">2</span></span></span></span></span></span></span></span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.345em;"><span></span></span></span></span></span><spanclass="mclosenulldelimiter"></span></span></span></span><spanstyle="top:−3.29em;"><spanclass="pstrut"style="height:3.06em;"></span><spanclass="frac−line"style="border−bottom−width:0.04em;"></span></span><spanstyle="top:−3.795em;"><spanclass="pstrut"style="height:3.06em;"></span><spanclass="mord"><spanclass="mop"><spanclass="mopop−symbolsmall−op"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.8043em;"><spanstyle="top:−2.4003em;margin−left:0em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−3.2029em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.2997em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.1667em;"></span><spanclass="mord"><spanclass="mordmathnormal"style="margin−right:0.03588em;">y</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.3117em;"><spanstyle="top:−2.55em;margin−left:−0.0359em;margin−right:0.05em;"><spanclass="pstrut"style="height:2.7em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmathnormalmtight">i</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.15em;"><span></span></span></span></span></span></span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mbin">−</span><spanclass="mspace"style="margin−right:0.2222em;"></span><spanclass="mord"><spanclass="mopennulldelimiter"></span><spanclass="mfrac"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:1.06em;"><spanstyle="top:−2.655em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span><spanstyle="top:−3.23em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="frac−line"style="border−bottom−width:0.04em;"></span></span><spanstyle="top:−3.535em;"><spanclass="pstrut"style="height:3em;"></span><spanclass="sizingreset−size6size3mtight"><spanclass="mordmtight"><spanclass="mopmtight"><spanclass="mopop−symbolsmall−opmtight"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7385em;"><spanstyle="top:−2.1786em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−2.931em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3214em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mopmtight"><spanclass="mopop−symbolsmall−opmtight"style="position:relative;top:0em;">∑</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.7385em;"><spanstyle="top:−2.1786em;margin−left:0em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">i</span><spanclass="mrelmtight">=</span><spanclass="mordmtight">1</span></span></span></span><spanstyle="top:−2.931em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmtight"><spanclass="mordmathnormalmtight">n</span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.3214em;"><span></span></span></span></span></span></span><spanclass="mspacemtight"style="margin−right:0.1952em;"></span><spanclass="mordmtight"><spanclass="mordmathnormalmtight"style="margin−right:0.03588em;">y</span><spanclass="msupsub"><spanclass="vlist−tvlist−t2"><spanclass="vlist−r"><spanclass="vlist"style="height:0.3281em;"><spanstyle="top:−2.357em;margin−left:−0.0359em;margin−right:0.0714em;"><spanclass="pstrut"style="height:2.5em;"></span><spanclass="sizingreset−size3size1mtight"><spanclass="mordmathnormalmtight">i</span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.143em;"><span></span></span></span></span></span></span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:0.345em;"><span></span></span></span></span></span><spanclass="mclosenulldelimiter"></span></span></span></span></span><spanclass="vlist−s">​</span></span><spanclass="vlist−r"><spanclass="vlist"style="height:1.295em;"><span></span></span></span></span></span><spanclass="mclosenulldelimiter"></span></span></span></span></span></span></p><h2><strong>Q:Whatisthesignificanceofthequarticfunctioninreal−worldapplications?</strong></h2><p>A:Thequarticfunctionhassignificantapplicationsinvariousfieldssuchasphysics,engineering,andeconomics.Forexample,itisusedtomodelthemotionofobjectsundertheinfluenceofgravity,todescribethebehaviorofelectricalcircuits,andtopredictthegrowthofpopulations.</p><h2><strong>Q:HowdoIdeterminethebestfitquarticfunctionforagivendataset?</strong></h2><p>A:Todeterminethebestfitquarticfunctionforagivendataset,youneedtousethemethodofleastsquarestocalculatethecoefficientsofthefunction.Youcanthenusethesecoefficientstoplotthefunctionandcompareitwiththegivendatapoints.</p><h2><strong>Q:Whatarethelimitationsofthemethodofleastsquares?</strong></h2><p>A:Themethodofleastsquareshasseverallimitations.Forexample,itassumesthattheerrorsinthedatapointsarenormallydistributed,whichmaynotalwaysbethecase.Additionally,itcanbesensitivetooutliersinthedata,whichcanaffecttheaccuracyoftheresults.</p><h2><strong>Q:HowdoIhandleoutliersinthedatawhenusingthemethodofleastsquares?</strong></h2><p>A:Tohandleoutliersinthedata,youcanusetechniquessuchasdatatransformation,datacleaning,androbustregression.Thesetechniquescanhelptoreducetheimpactofoutliersontheresultsandimprovetheaccuracyofthemodel.</p><h2><strong>Q:Whataresomecommonapplicationsofthequarticfunctioninmathematics?</strong></h2><p>A:Thequarticfunctionhasseveralapplicationsinmathematics,including:</p><ul><li>Modelingthemotionofobjectsundertheinfluenceofgravity</li><li>Describingthebehaviorofelectricalcircuits</li><li>Predictingthegrowthofpopulations</li><li>Solvingsystemsofequations</li><li>Findingtherootsofpolynomials</li></ul><h2><strong>Q:HowdoIusethequarticfunctiontosolvesystemsofequations?</strong></h2><p>A:Tousethequarticfunctiontosolvesystemsofequations,youneedtofirstwritethesystemofequationsintheformofaquarticequation.Youcanthenusethemethodofleastsquarestocalculatethecoefficientsofthequarticfunctionandsolvefortherootsoftheequation.</p>