(Continues Exercise 7 in Section 8.3.) To try to improve the prediction of FEV1, additional independent variables are included in the model. These new variables are Weight (in kg), the product (interaction) of Height and Weight, and the ambient temperature (in ◦C). The following MINITAB output presents results of fitting the model FEV1 =????0 + ????1 Last FEV1 + ????2 Gender + ????3 Height + ????4 Weight + ????5 Height ⋅ Weight

+ ????6 Temperature + ????7 Pressure + ????

The regression equation is FEV1 = -0.257 + 0.778 Last FEV - 0.105 Gender + 1.213 Height - 0.00624 Weight

+ 0.00386 Height*Weight - 0.00740 Temp - 0.00148 Pressure Predictor Coef StDev T P Constant -0.2565 0.7602 -0.34 0.736 Last FEV 0.77818 0.05270 14.77 0.000