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 Stream (survival probability of patients treated by the drug) and Spiaoebo (Survival probability of patients given a placebo) are determined to 15! be: Striated\") : E(f and Spfmbalft) Z LEEm. {a} (3 marks) Use the given function 15 Splacebo(t) = e' to calculate the average survival probability of the placebo group for the first 10 months of the study. Round to 2 decimal places. L Survlval probatlill'ly , (b) (3 marks) The efficacy ofthe drug at any timer 12 {Jean be defined as Eh") = A (Smmd) Sambtt)} dt. Note: This can be thought of as representing a differeme of areas. Use a Riemann sum with 5 sub-intervals of equal width to approximate E[1{)). Use right endpoints. Round your final answer to 2 decimal places. (c) {1 mark} A drug is beneficial if Eh) > 0 (meaning treated Subjects have a larger average Survival time mr the first 1- months}. Is the drug beneficial at 10 menths? (A short lane-sentence answer is encugh.) (d) {1 mark) Is the drug beneficial at 1' = 20? Explain in 1 or 2 sentences