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.

$\begin{array} { l | c }
& \text { Coefficients } \
\hline \text { Intercept } & 38.3949789 \
\hline \text { Speed } & - 0.18832886
\end{array}$
Write the equation of the least-squares regression line.

A) y=-38.394979+0.18832886 x
B) y=38.3949789-0.18832886 x
C) y=38.3949789+0.18832886 x
D) y=-0.18832886+38.3949789 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.

$\begin{array} { l | c } 
& \text { Coefficients } \
\hline \text { Intercept } & 38.3949789 \
\hline \text { Speed } & - 0.18832886
\end{array}$
Write the equation of the least-squares regression line.

A) y=-38.394979+0.18832886 x
B) y=38.3949789-0.18832886 x
C) y=38.3949789+0.18832886 x
D) y=-0.18832886+38.3949789 x

Quizplus · Accepted Answer

The equation of the least-squares regression line is given by $y = a + bx$, where $a$ is the intercept and $b$ is the slope. Here, $a = 38.3949789$ and $b = -0.18832886$, so the equation is $y = 38.3949789 - 0.18832886x$.