A study was done to assess the cost eectiveness of driving

Chapter 12, Problem 12.45

(choose chapter or problem)

A study was done to assess the cost eectiveness of driving a four-door sedan instead of a van or an SUV (sports utility vehicle). The continuous variables are odometer reading and octane of the gasoline used. The response variable is miles per gallon. The data are presented here. MPG Car Type Odometer Octane 34.5 sedan 75,000 87.5 33.3 sedan 60,000 87.5 30.4 sedan 88,000 78.0 32.8 sedan 15,000 78.0 35.0 sedan 25,000 90.0 29.0 sedan 35,000 78.0 32.5 sedan 102,000 90.0 29.6 sedan 98,000 87.5 16.8 van 56,000 87.5 19.2 van 72,000 90.0 22.6 van 14,500 87.5 24.4 van 22,000 90.0 20.7 van 66,500 78.0 25.1 van 35,000 90.0 18.8 van 97,500 87.5 15.8 van 65,500 78.0 17.4 van 42,000 78.0 15.6 SUV 65,000 78.0 17.3 SUV 55,500 87.5 20.8 SUV 26,500 87.5 22.2 SUV 11,500 90.0 16.5 SUV 38,000 78.0 21.3 SUV 77,500 90.0 20.7 SUV 19,500 78.0 24.1 SUV 87,000 90.0 (a) Fit a linear regression model including two indicator variables. Use (0,0) to denote the four-door sedan. (b) Which type of vehicle appears to get the best gas mileage?(c) Discuss the dierence between a van and an SUV in terms of gas mileage.