placebo group), tot_plac (total number of participants in the placebo group), dth_asp (number of participants that died in the aspirin group), and tot_asp (total number of participants in the aspirin group). Use the data in this table to answer the questions below the table. XStudy dth_plac tot_plac dth_asp tot_asp Elwood_etal_1974 67 624 49 615 Coronary_1976 64 77 44 757 Elwood_Sweetman_1979 126 850 102 832 Breddin_etal_1979 38 309 32 317 Persantine_1980 52 406 85 810 Aspirin_1980 219 2257 346 2267 ISIS2_1988 1720 8600 1570 8587 a. Conduct the appropriate statistical test to determine whether the proportion that died in the aspirin group was greater than the proportion that died in the placebo group for the Aspirin_1980 study. Assume a=0.05. Show all calculations. [ 2 Marks] b. Conduct the appropriate statistical test to determine whether there is an association between treatment group (aspirin, placebo) and deaths (yeso) in the Elwood_Sweetman_1979 study. Assume a=0.05. Show all calculations. [ 2 Marks] c. You have been asked to conduct a meta-analysis of the data in the above table, in order to determine whether the proportion that died in those that received aspirin was lower than the proportion that died in those that received a placebo. Conduct the appropriate statistical test, assuming a=0.05. Show all calculations. [2 Marks] 3. A clinical trial was conducted in which 50 patients were randomly assigned to one of five cholesterol-reducing drug regimens. Three of the drug regimens involved the same drug administered as 20 mg once per day (Itime), 10 mg twice per day (2times), or 5 mg four times per day (4times). The two remaining drug regimens (drugD and drugE) represented competing drugs. Previous studies have shown that cholesterol reduction is approximately normally distributed with equal variance across patients receiving a range of different cholesterol-reducing drugs. The data set for the trial is in the Data folder in A2L Contents, is called Q3_CHOL, and has two variables: trt (indicating drug regimen) and response (indicating cholesterol reduction in mmol/1). Use these data to answer the questions below. Assume a=0.05. a. Create a box & whisker plot to compare the cholesterol reduction levels across the five treatment groups. Comment on the pattern you see in cholesterol reduction across the treatment groups. [2 Marks]