A calculator was used to perform a linear regression on the values in the table. The results are shown to the right of the table.

\begin{tabular}{|c|c|}
\hline [tex]$x$[/tex] & [tex]$y$[/tex] \\
\hline 1 & 10 \\
\hline 2 & 7 \\
\hline 3 & 3 \\
\hline 4 & 0 \\
\hline 5 & -2 \\
\hline
\end{tabular}

LinReg: [tex]$y = ax + b$[/tex] \\
[tex]$a = -3.1$[/tex] \\
[tex]$b = 12.9$[/tex] \\
[tex]$r^2 = 0.9886831276$[/tex] \\
[tex]$r = -0.9943254636$[/tex]

What is the line of best fit?

A. [tex]$y = -3.1x + 12.9$[/tex] \\
B. [tex]$y = -0.994x + 12.9$[/tex] \\
C. [tex]$y = 12.9x - 3.1$[/tex] \\
D. [tex]$-0.994 = -3.1x + 12.9$[/tex]



Answer :

To determine the line of best fit derived from the linear regression analysis given in the results, follow these steps:

1. Understand the Linear Regression Equation: The general formula for a linear regression line is [tex]\( y = ax + b \)[/tex], where:
- [tex]\( a \)[/tex] is the slope of the line.
- [tex]\( b \)[/tex] is the y-intercept.

2. Identify the Given Values from the Problem:
- Slope ([tex]\( a \)[/tex]): -3.1
- Y-intercept ([tex]\( b \)[/tex]): 12.9

3. Formulate the Best Fit Line Equation:
Using the identified values, substitute them into the linear regression equation:
[tex]\[ y = -3.1x + 12.9 \][/tex]

4. Review the Provided Choices:
Compare the derived equation with the options given:
- A. [tex]\( y = -3.1x + 12.9 \)[/tex]
- B. [tex]\( y = -0.994x + 12.9 \)[/tex]
- C. [tex]\( y = 12.9x - 3.1 \)[/tex]
- D. [tex]\( -0.994 = -3.1x + 12.9 \)[/tex]

5. Select the Correct Option:
The line of best fit equation [tex]\( y = -3.1x + 12.9 \)[/tex] matches option A.

Thus, the line of best fit is:
[tex]\[ \boxed{A. \ y=-3.1x+12.9} \][/tex]