31. The Buyer's Guide section of the Web site for Car and Driver magazine provides reviews and road tests for cars, trucks, SUVs, and vans. The average ratings of overall quality, vehi- cle styling, braking, handling, fuel economy, interior comfort, acceleration, dependability, fit and finish, transmission, and ride are summarized for each vehicle using a scale rang- ing from 1 (worst) to 10 (best). A portion of the data for 14 Sports/GT cars is shown here (http://www.caranddriver.com, January 7, 2004).

Sports/GT Overall Handling Dependability Fit and Finish Acura 3.2CL 7.80 7.83 8.17 7.67 Acura RSX 9.02 9.46 9.35 8.97 Audi TT 9.00 9.58 8.74 9.38 BMW 3-Series/M3 8.39 9.52 8.39 8.55 Chevrolet Corvette 8.82 9.64 8.54 7.87 Ford Mustang 8.34 8.85 8.70 7.34 Honda Civic Si 8.92 9.31 9.50 7.93 Infiniti G35 8.70 9.34 8.96 8.07 Mazda RX-8 8.58 9.79 8.96 8.12 Mini Cooper 8.76 10.00 8.69 8.33 Mitsubishi Eclipse 8.17 8.95 8.25 7.36 Nissan 350Z 8.07 9.35 7.56 8.21 Porsche 911 9.55 9.91 8.86 9.55 Toyota Celica 8.77 9.29 9.04 7.97

a. Develop an estimated regression equation using handling, dependability, and fit and finish to predict overall quality.

b. Another Sports/GT car rated by Car and Driver is the Honda Accord. The ratings for handling, dependability, and fit and finish for the Honda Accord were 8.28, 9.06, and 8.07, respectively. Estimate the overall rating for this car.

c. Provide a 95% confidence interval for overall quality for all sports and GT cars with the characteristics listed in part (a).

d. Provide a 95% prediction interval for overall quality for the Honda Accord described in part (b).

e. The overall rating reported by Car and Driver for the Honda Accord was 8.65. How does this rating compare to the estimates you developed in parts

(b) and (d)?