REGRESSION 1 mpginy Dependent Variable: Independent Variables: hp Regression Statistics: R-Squared 0.731 Adj.R-Sqr. 0.730 Std.Err.Reg. 0.008646 Std.Dep.Var. 0.017 # Fitted 392 Coefficient Estimates: Variable Constant hp Coefficient 0.009218 0.000370 Std.Err. 0.001265 0.000011 t-Statistic 7.290 32.530 P-value 0.000 0.000 Forecasts: hp Forecast 0.035 0.039 0.042 0.046 0.050 0.054 0.057 0.061 0.065 StErrFcst 0.008666 0.008661 0.008659 0.008657 0.008657 0.008659 0.008662 0.008666 0.008672 70 80 90 100 110 120 130 140 150 2. Macy is interested in predicting gasoline consumption in cars as a function of their power. She has collected a random sample of 392 automobile models; each observation includes mpg (miles per gallon consumed), and hp (horse power produced). After concluding the relationship is not linear, she focused on a regression of mpginv (defined as 1/mpg) on hp. NOTE, that to turn mpginv back to mpg remember 1: mpginy, therefore 1 - mpginy mpg. The output for that regression is provided in a separate sheet and labeled REGRESSION 1. mpg = (a) Based on the REGRESSION 1 output, construct a 95% confidence interval for the miles per gallon of a car that has horse power equal to 110. (4 points) (b) Macy's boss looks at the REGRESSION 1 output, and concludes that something must be wrong with this data because it shows no relationship between gasoline consumption and horse power. Briefly comment as to whether you agree or disagree with Macy's boss and why. (4 points) REGRESSION 1 mpginy Dependent Variable: Independent Variables: hp Regression Statistics: R-Squared 0.731 Adj.R-Sqr. 0.730 Std.Err.Reg. 0.008646 Std.Dep.Var. 0.017 # Fitted 392 Coefficient Estimates: Variable Constant hp Coefficient 0.009218 0.000370 Std.Err. 0.001265 0.000011 t-Statistic 7.290 32.530 P-value 0.000 0.000 Forecasts: hp Forecast 0.035 0.039 0.042 0.046 0.050 0.054 0.057 0.061 0.065 StErrFcst 0.008666 0.008661 0.008659 0.008657 0.008657 0.008659 0.008662 0.008666 0.008672 70 80 90 100 110 120 130 140 150 2. Macy is interested in predicting gasoline consumption in cars as a function of their power. She has collected a random sample of 392 automobile models; each observation includes mpg (miles per gallon consumed), and hp (horse power produced). After concluding the relationship is not linear, she focused on a regression of mpginv (defined as 1/mpg) on hp. NOTE, that to turn mpginv back to mpg remember 1: mpginy, therefore 1 - mpginy mpg. The output for that regression is provided in a separate sheet and labeled REGRESSION 1. mpg = (a) Based on the REGRESSION 1 output, construct a 95% confidence interval for the miles per gallon of a car that has horse power equal to 110. (4 points) (b) Macy's boss looks at the REGRESSION 1 output, and concludes that something must be wrong with this data because it shows no relationship between gasoline consumption and horse power. Briefly comment as to whether you agree or disagree with Macy's boss and why. (4 points)
