The problems on this assignment require you to find and compare survival between groups. Answer all questions specified on the problem but if you see something interesting and want to do more analysis please report it as well. Discussion on all output is expected. The output you generate along with your comments and answers to questions should be on a separate file from the R-code which generated the output.
Q 1. An investigator collected data on survival of patients with lung cancer at Mayo Clinic.The investigator would like you, the statistician, to answer the following questions and provide some graphs. The data is located in the survival package under the name:cancer
a. What is the probability that someone will survive past 300 days?
b. Provide a graph, including 95% confidence limits, of the Kaplan-Meier estimator the entire study.
c. Is there a difference in the survival rates between males and females? Provide formal statistical test with p-value and visual evidence.
d. Is there a difference in the survival rates for the older half of the group versus the younger half? Provide a formal statistical test with p-value and visual evidence
Q 2. The mastectomy data from the HSAUR3 package are the survival times (in months) after mastectomy of women with breast cancer. The cancers are classified as having metastised or not based on a histochemical marker.
a. Plot the survivor functions of each group, estimated using the Kaplan-Meier estimate, on the same graph and comment on the differences.
b. Use a log-rank test to compare the survival experience of each group more formally