2. The data in the table below came from randomized controlled trials that tested the effectiveness of Aspirin (versus placebo ) in preventing death after a myocardial infarction (MI ). The data from these studies were collected for the purpose of conducting a meta - analysis for a systematic review on the effectiveness of Aspirin . The purpose of a meta - analysis is to pool (combine ) the data from multiple studies in order to provide an estimate of the treatment effect across the pooled studies . The labels in the table refer to the following : Study (study reference ), dth_plac (number of participants that died in the 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 49 515 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 15152 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 o=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 (yes o ) 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 o=0.05 . Show all calculations . [2 Marks ]