\f2.4 PANKRATZ . Forecasting with of least-squares estimate aid="5N5AR">Table B.3 presents data on the gasoline mileage performance of 32 different automobiles. a. Fit a simple linear regression model relating gasoline mileage y(miles per gallon) to engine displacement x1 (cubic inches). b. Construct the analysis-of-variance table and test for significance of a regression. c. What percent of the total variability in gasoline mileage is accounted for by the linear relationship with engine displacement? d. Find a 95% CI on the mean gasoline mileage if the engine displacement is 275 in^3. e. Suppose that we wish to predict the gasoline mileage obtained from a car with a 275-in' engine. Give a point estimate of mileage. Find a 95% prediction interval on the mileage. f. Compare the two intervals obtained in parts d and e. Explain the difference between them. Which one is wider, and why