Use the simulated data on peak flow of water used in the exercises in Chapter 5. Use LQ = ln(Q) as the dependent variable with the logarithms of the nine independent variables. Repeat Exercise 7.8...

Use the simulated data on peak flow of water used in the exercises in Chapter 5. Use LQ = ln(Q) as the dependent variable with the logarithms of the nine independent variables. Repeat Exercise 7.8 using the stepwise method of variable selection. Use SLE = .50 and SLS = .20 for elimination of a variable from the model. What subset model is selected? Plot the Cp statistic for the models used to decide which model to adopt. Do you arrive at the same model as with forward selection? As with backward elimination?

Exercise 7.8

Use the simulated data on peak flow of water used in the exercises in Chapter 5. Use LQ = ln(Q) as the dependent variable with the logarithms of the nine independent variables. Use a forward selection variable selection method to search for an acceptable model for the peak flow data. Use SLE = .50 for entry of a variable into the model. What subset would you select if you used SLE = .15? Compute and plot the C_p
statistic for the models from SLE = .50. What subset model do you select for prediction using C_p?