Question: 19. Refer to problem 14.13 above. Assume that the fitted model is appropriate and that large-sample inferences are applicable.

b. Use the Wald test to determine whether X₂, age of oldest family automobile, can be dropped from the regression model: use α = .05. State the alternatives, decision rule, and conclusion. What is the approximate P – value of the test?

c. Use the likelihood ratio to determine whether X₂, age of oldest family automobile, can be dropped from the regression model: use α = .05. State the full and reduced models, decision rule, and conclusion. What is the approximate P – value of the test? How does the result here compare to that obtained for the Wald test in (b)?

e. Show -2logLR for this model and degrees of freedom.

Hint: This is an indicator of the difference in fit between this model and the saturated model.

f. How well does this model explain Y? Show four measures of the model fits.