Small cars offer higher fuel efficiency, are easy to maneuver and park, and have generally performed well in road tests. The following data show the overall fuel efficiency rating (miles per gallon), predicted reliability (highest = 5), safety rating (highest = 5), and the price ($) for 20 small cars (Consumer Reports, March 2009).

a. Determine the estimated regression equation that can be used to predict the price of a small car given its overall fuel efficiency rating, predicted reliability, and safety rating.
b. Use the F test to determine the overall significance of the relationship. What is the conclusion at the .05 level of significance?
c. Use the t test to determine the significance of each independent variable. What is your conclusion at the .05 level of significance?
d. Remove any independent variable that is not significant from the estimated regression equation. What is your recommended estimated regression equation? Compare the value of R2 for this estimated regression equation with the value of R2 for the estimated regression equation from part (a). Discuss the differences.

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Price () 16,205 17,450 18,490 17,440 19,610 18,810 16,730 14,230 17,555 17,980 16,185 15.185 16,675 16,130 16,620 15,820 17,378 16,419 18,404 16,095 Make & Model MPG 25 24 Reliability Safety Chevrolct Avco LT Chevrolet Cobalt LT Ford Focus SES Ford Focus SES (MT) Honda Civic EX Honda Civic EX (MT) Honda Fit Sport (MT) Hyundai Accent GLS Hyundai Elantra GLS Hyundai Elantra SE Kia Spectra EX Kia Spectra EX (MT) Nissan Versa 1.8 SL Nissan Versa 1.85 Scion xID Scion xD (MT Suzuki SX4 LE Toyota Corolla (base, MT) Toyota Corolla LE Toyota Yaris Hatchback 28 28 27 25 28 28 34 32