Using R language to do the question A recently developed drug, MediCo, has been used over the past 12 months to treat a potentially fatal disease. MediCo was approved by a medical regulator last year following initial trials and mortality data has been collected over the past 12 months, since approval, to continue reviewing the drug's effectiveness. This mortality data has been compared with mortality data collected from infected patients, prior to MediCo's approval, who were NOT administered the drug. It is suspected that gender may be a significant covariate on the mortality rate of infected patients. Data Life Drug Gender Status Time 85 67 10 283 0 0 0 0 0 0 0 0 0 58 DONOURWN 108 9 160 23 Life Unique patient identifier (integers 1, 2, .., 4,400) Drug Drug indicator (1 = received drug, 0 = did not receive drug) Gender Gender indicator (1 = female, 0 = male) Status Status indicator (1 = death due to disease, 0 = censoring event occurred) Time Duration in days at which death/censoring occurred (integers with a range of 1-365, with 1 = first day of the investigation and 365 = last day of the investigation). a) Plot the Kaplan-Meier survival function estimate for all patients, together with its two-sided 99.5% confidence interval. b) Determine, using the estimated survival function from part (a), the probability that a patient survived from the beginning of the investigation to the end of the investigation. c) Plot, on a single graph, four Kaplan-Meier survival function estimates without any confidence intervals, where each estimate represents one of the four possible patient group combinations of drug and gender. You should use separate colours to identify each survival function. d) Estimate a Cox proportional hazards model with death as the event of interest using the two covariates, drug, and gender, with no interaction term, pasting your results into your answer script