Gas mileage As the example in the chapter indicates, one of the important factors determining a car’s Fuel Efficiency is its Weight. Let’s examine this relationship again, for 11 cars.

a) Describe the association between these variables shown in the scatterplot on the next page.

b) Here is the regression analysis for the linear model.
What does the slope of the line say about this relationship?

c) Do you think this linear model is appropriate? Use the residuals plot to explain your decision.

Fuel Efficiency (mpg) 32 20 28 24 20+ + + + 2.0 2.5 3.0 3.5 Weight (1000 lb)