Answer Happy

3 The article, Remdesivir in adults with severe COVID-19: a randomised, double-blind, placebo-controlled, multicentre trial, Lancet, 395(10236), pp. 1569–1578, May 16, 2020, by Y. Wang and et. al., reports the following study for the treatment of severe cases of SARS-CoV-2 virus infection with an experimental medicine, Remdesivir, originally made for Ebola. "237 patients were enrolled and randomly assigned to a treatment group or a control group (158 to Remdesivir and 79 to placebo)." The results of the study includes the 28 day mortality rates of 13.9% for the Remdesivir group and 12.8% for the control group, and the 28 day clinical improvement rates of 65.2% for the Remdesivir group and 57.7% for the control group. Be sure to justify all steps both analytically and graphically. (a) Find the 96% confidence interval of the difference of the 28 day clinical improvement rate between the two groups. (b) Does the study suggest that Remdesivir helped improving the 28 day clinical improve- ment rate? Set up your hypotheses and test them with the significance level of a = 0.05.