In a study of bladder cancer, tumors were removed from the bladders of 86 patients. Subsequently, the individuals were assigned to be treated with either a placebo or the drug thiopeta. Time to recurrence of tumor in months is saved under the variable name time in the data set bladder. Treatment status is saved under the name group; the 1 value represents placebo. Indicators of censoring status; where 0 indicates a tumor did not occur and the observation was censored, is saved under the name censor.
a. Use the product-limit method to estimate the survival function in each treatment group.
b. Plot a survival curve--do not submit.
c. Does it appear that the individuals in one group have a longer time to first recurrence than in the other group?