Problem
Suppose the survival times (in months since transplant) for eight patients who received bone marrow transplants are 3.0, 4.5, 6.0, 11.0, 18.5, 20.0, 28.0, and 36.0. Assume no censoring.
a) What is the median survival time?
b) What is the mean survival time?
c) Using 5 months as the interval, construct a life table for these data.
d) Calculate a Kaplan-Meier curve for the survival distribution.
e) Fit a negative exponential survival model to the data.
f) Compare the fitted exponential to the Kaplan-Meier curve at the eight event times.
g) Based on the comparison in 6, would you say the exponential is a good fit?