Question

The Tire Rack, America's leading online distributor of tires and wheels, conducts extensive testing to provide customers with products that are right for their vehicle, driving style, and driving conditions. In addition, the Tire Rack maintains an independent consumer survey to help drivers help each other by sharing their long-term tire experiences. The following data show survey ratings (1 to 10 scale with 10 the highest rating) for 18 maximum performance summer tires (Tire Rack website, February 3, 2009). The variable Steering rates the tire's steering responsiveness, Tread Wear rates quickness of wear based on the driver's expectations, and Buy Again rates the driver's overall tire satisfaction and desire to purchase the same tire again. Click on the datafile logo to reference the data.

Buy Tire Tread Wear 8.6 Dry Traction 9.0 Steering Again? 8.0 8.5 8.5 9.3 8.8 7.5 8.9 7.3 7.2. 7.4 7.9 7) 8.4 Sumitomo HTR A/S PO2 Goodyear Eagle Sport All-Season Michelin Pilot Sport A/S 3 Kumho Ecsta PA31 Firestone Firehawk Wide Oval AS BFGoodrich g-Force Super Sport A/S Yokohama AVID ENVigor Goodyear Eagle RS-A2 Hankook Ventus V2 concept2 Firestone Firehawk GT Firestone FR740 Dunlop SP Sport 7000 A/S Goodyear Eagle RS-A Bridgestone Potenza RE92A Yokohama ADVAN A83A Bridgestone Potenza RE92 Firestone Firehawk GTA-03 6.4 6.6 7.1 7.9 6.1 5.1 7.5 7.0 6.5 7.6 6,9 Round your answers to four decimal places. a. Develop an estimated regression equation that can be used to predict the Buy Again rating given based on the Tread Wear rating. ® Tread Wear At the .01 level of significance, test for a significant relationship. There is a significant relationship b. Did the estimated regression equation developed in part (a) provide a good fit to the data? Yes Explain. The input in the box below will not be graded, but may be reviewed and considered by your instructor. blank c. Develop an estimated multiple regression equation that can be used to predict the Buy Again rating given the Tread Wear rating and the Dry Traction rating. ŷ=- + Tread Wear + Dry Traction d. Is the addition of the Dry Traction independent variable significant? Use a =.01. Yes e. Develop an estimated multiple regression equation that can be used to predict the Buy Again rating given the Tread Wear rating, the Dry Traction rating, and the Steering rating ŷ=- O Tread Wear + O Dry Traction - Steering rating