2. (18 points) Re-consider the burn data in R package KMSurv on the times until staphylococcus infection of burn patients. Use the variables 21 (Treatment: O-routine bathing 1-Body cleans- ing), T3 (Time to straphylocous aureaus infection or on study time) and D3 (Straphylocous aureaus infection: 1=yes (=no) for the problems. (a) (8 points) Using the log-rank test, test the hypothesis of no difference in the rate of staphy- lococcus infection between patients whose burns were cared for with a routine bathing care method versus those whose body cleansing was initially performed using 4% chlorhexidine gluconate. Use a two-sided test and a 0.05 significance level. (b) (8 points) Repeat the test using Gehan's test. (c) (2 points) How does the result from logrank test compare with that from Gehan's test? Why? You may consider the plots of estimated survival functions and weighting in these two tests. 2. (18 points) Re-consider the burn data in R package KMSurv on the times until staphylococcus infection of burn patients. Use the variables 21 (Treatment: O-routine bathing 1-Body cleans- ing), T3 (Time to straphylocous aureaus infection or on study time) and D3 (Straphylocous aureaus infection: 1=yes (=no) for the problems. (a) (8 points) Using the log-rank test, test the hypothesis of no difference in the rate of staphy- lococcus infection between patients whose burns were cared for with a routine bathing care method versus those whose body cleansing was initially performed using 4% chlorhexidine gluconate. Use a two-sided test and a 0.05 significance level. (b) (8 points) Repeat the test using Gehan's test. (c) (2 points) How does the result from logrank test compare with that from Gehan's test? Why? You may consider the plots of estimated survival functions and weighting in these two tests