33. A consumer advocacy group recorded several variables on 140 models of cars. The resulting information was used to produce the following regression output that relates the city gas mileage (in mpg) and the engine displacement (in cubic inches). The regression equation is mpg:city = 33.4 - 0.0624 displacement Predictor Coof SE Coof T Constant 33 . 4 0. 7762 43.00 0.000 displacement -0. 0624 0. 003810 0.000 S = 3. 13923 R-Sq = 66.08 R-Sq (adj) = 65. 8% a. (5 points) We have a car that has an engine with 150 cubic inches. Based on this output, what city gas mileage would you predict for this car? Answer: b. (5 points) Based on this output what is the correlation between city gas mileage and displacement? Answer: c. (5 points) The test statistics for testing the slope is zero is missing. Calculate this value: Answer: The group also recorded the power of the engine (in horsepower) for each car. The following regression output was produced. The regression equation is mpg :city = 32.2 - 0.0572 horsepower Predictor Coof SE Coof T Constant 32.2 1.000 32.19 0. 000 horsepower -0. 05 72 0. 005022 -11.39 0. 000 S = 3. 86688 R-Sq = 48. 48 R-Sq (adj) = 48. 18 d. (5 points) Which of the variables (horsepower or displacement) would be the better predictor of city gas mileage? Explain