Exercise 18.2 You are given the following information with respect to a Kaplan-Meier estimate of a survival function S. (t(5)) = 0.87500, (+6)) = 0.8500 and $(t(m)) = 0.82875. At each time of death t), there is one death. (a) Calculate the risk set at time t6). (b) There were two exits from the risk set between times to and t(7). How many new entrants were there in this period? Exercise 18.2 You are given the following information with respect to a Kaplan-Meier estimate of a survival function S. (t(5)) = 0.87500, (+6)) = 0.8500 and $(t(m)) = 0.82875. At each time of death t), there is one death. (a) Calculate the risk set at time t6). (b) There were two exits from the risk set between times to and t(7). How many new entrants were there in this period