Consider the survival times from 30 resected melanoma patients in Table 3.1. Let AGEG denote age group, AGEG=1 if age 45 and AGEG= 2 otherwise. Fit the survival times with an AGEG-stratified Cox...

Consider the survival times from 30 resected melanoma patients in Table 3.1. Let AGEG denote age group, AGEG=1 if age
45 and AGEG= 2 otherwise. Fit the survival times with an AGEG-stratified Cox proportional hazards model with the covariates age, gender, initial stage, and treatment received. Discuss the association of the treatment received with the survival time.