The data for this question contain remission times of 42 multiple leukemia patients in a clinical trial of a new treatment. The variables in the dataset are given below:

Variable 1: survival time (in weeks)

Variable 2: status (l=remission, 0=relapse)

Variable 3: sex (l=female, 0=male)

Variable 4: log WBC

Variable 5:Rxstatus (l=placebo, 0=treatment)

Below, we provide computer results for several different Cox models that were fit to this dataset. A number of questions will be asked about these results starting below.