Chapter 8, Problem 4E

To determine

To explain what does it mean to say that a certain car has a positive residual.

Explanation of Solution

In the previous question it is given that, we examined in previous exercise about the relationship between the fuel economy in mpg and horsepower for models of cars. Thus, the analysis produced the regression model for the same:

  $\text{<mover accent="true"><mo>m</mo><mo>^</mo></mover> pg}=46.87-0.084\text{HP}$

Thus, by saying that a certain car has a positive residual, it means that the mpg is higher than the model predicts for cars with that horsepower.