Question: a. Construct the plot of the deviance residuals against i for the Table 15.5 data after first deleting point 17.
b. Construct the plot of the modified deviance residuals against i for the data in Table 15.5, using the full data set. Does the plot seem to highlight points that are not well fit by the model?
c. Consider the conclusion in Section 15.4 for the model using Y in binary form versus the conclusion when the actual values of Y were used. What would we expect to happen in general when either an independent variable or the dependent variable in a regression analysis is dichotomized?
d. If available, use the software package LogXact to obtain the exact standard errors of the estimators for the logistic regression model. Then use other available software to obtain the asymptotic standard errors, and compare the results. Is the exact approach necessary for this data set?
