Consider the regression of mileage for certain automobiles, measured in miles per gallon (mpg) on their weight in pounds (wt). The data are from Consumer Reports (April 1997). Part of the SAS output from the procedure is shown in Figure.
(a) Estimate the mileage for a vehicle weighing 4000 pounds.
(b) Suppose that the Honda engineers claim that, on average, the Civic (or any other model car weighing 2440 pounds) gets more than 30 mpg. Based on the results of the regression analysis, would you believe that claim? Why or why not?
(c) The design engineers for the Lexus ES300 targeted 18 mpg as being ideal for this model (or any other model weighing 3390 pounds) although it is expected that some variation will be experienced. Is it likely that this target value is realistic? Discuss.