The following table shows the per-person carbon dioxide emissions for the United States and for the rest of the world over six years.
$\begin{array} { c c }
\text { Non-U.S. } & \text { U.S. } \
4.2 & 18 \
3.8 & 17.5 \
4 & 17 \
3 & 18.6 \
3.9 & 17.5 \
3.8 & 16.5
\end{array}$
The least-squares regression equation is $y = 20.9878 - 0.9175 x$ . If the non-U.S. emissions differ by 0.5 From one year to the next, by how much would you predict the U.S. emissions to differ?
A) -0.92
B) 0.46
C) -1.83
D) -0.46

Question

The following table shows the per-person carbon dioxide emissions for the United States and for the rest of the world over six years. 
$\begin{array} { c c } 
\text { Non-U.S. } & \text { U.S. } \
4.2 & 18 \
3.8 & 17.5 \
4 & 17 \
3 & 18.6 \
3.9 & 17.5 \
3.8 & 16.5
\end{array}$
 The least-squares regression equation is $y = 20.9878 - 0.9175 x$ . If the non-U.S. emissions differ by 0.5 From one year to the next, by how much would you predict the U.S. emissions to differ?
A) -0.92
B) 0.46
C) -1.83
D) -0.46

Quizplus · Accepted Answer

The least-squares regression equation given is $y = 20.9878 - 0.9175x$. The coefficient of $x$ (-0.9175) represents the change in $y$ (U.S. emissions) for each unit change in $x$ (non-U.S. emissions). Therefore, if non-U.S. emissions differ by 0.5, the predicted difference in U.S. emissions would be $0.5 \times -0.9175 = -0.45875$, which rounds to -0.46.

The Following Table Shows the Per-Person Carbon Dioxide Emissions for the United