5. A group of doctors are conducting a clinical trial for an experimental cancer drug. The graph below shows the probability of patient survival as a function of time, t (in months). The functions for Streated (survival probability of patients treated by the drug) and Splacebo ( survival probability of patients given a placebo) are determined to be: Streated (t) = e (12)" and Splacebo(t) = e- 144. 15t (a) (3 marks) Use the given function Splacebo(t) = e 14 to calculate the average survival probability of S treated Survival probability the placebo group for the first 10 months of the study. Round to 2 decimal places. -0.6 Splacebo -0:4 -0.2 10 15 20 (b) (3 marks) The efficacy of the drug at any time 7 2 0 can be defined as E(T) = (Streated(t) - Splacebo(t) ) dt. Note: This can be thought of as representing a difference of areas. Use a Riemann sum with 5 sub-intervals of equal width to approximate E(10). Use right endpoints. Round your final answer to 2 decimal places