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 timeI t (in months). The functions for Stream; (survival probability of patients treated by the drug) and 313mm (survival probability of patients given a placebo) are determined to 153 ha: Stream\") = _(%)2 and SPIQBBBO(t) = e_m_ (a) (3 marks) Use the given function Spimgm(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. Survival probability (b) (3 marks) The efficacy of the drug at any time T Z U can be defined as E{T) = f (Streggd) - SpicmebaUD dt. 0 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 13(10). Use right endpoints. Round your final answer to 2 decimal places. (c) (1 mark) A drug is beneficial if EU) > 0 (meaning treated subjects have a larger average survival time over the first 1' months). Is the drug beneficial at 10 months? (A short one-sentence answer is enough.) (d) (1 mark) Is the drug beneficial at 1' = 20? Explain in 1 or 2 sentences