An automotive engineer computed a least-squares regression line for predicting the gas mileage (mile per gallon) of a certain vehicle from its speed in mph. The results are presented in the following Excel output.
$\begin{array}{l|c}
& \text { Coefficients } \
\hline \text { Intercept } & 32.4881657 \
\hline \text { Speed } & -0.10266272
\end{array}$
Write the equation of the least-squares regression line.
A) $y = - 0.10266272 + 32.4881657 x$
B) $y = 32.4881657 + 0.10266272 x$
C) $y = - 32.488166 + 0.10266272 x$
D) $y = 32.4881657 - 0.10266272 x$

Question

An automotive engineer computed a least-squares regression line for predicting the gas mileage (mile per gallon) of a certain vehicle from its speed in mph. The results are presented in the following Excel output.
$\begin{array}{l|c} 
& \text { Coefficients } \
\hline \text { Intercept } & 32.4881657 \
\hline \text { Speed } & -0.10266272
\end{array}$
Write the equation of the least-squares regression line.
A) $y = - 0.10266272 + 32.4881657 x$
B) $y = 32.4881657 + 0.10266272 x$
C) $y = - 32.488166 + 0.10266272 x$
D) $y = 32.4881657 - 0.10266272 x$

Quizplus · Accepted Answer

The equation of the least-squares regression line is given by $y = \text{intercept} + \text{slope} \cdot x$, where the intercept is 32.4881657 and the slope (coefficient for speed) is -0.10266272, leading to $y = 32.4881657 - 0.10266272 x$.