A clinical trial is conducted to compare an experimental medication to placebo to reduce the symptoms of asthma. Two hundred participants are enrolled in the study and randomized to receive either the exper- imental medication or placebo.The primary outcome is a self-reported reduction of symptoms.Among 100 participants who receive the experimental medication, 38 report a reduction of symptoms as compared to 21 participants of 100 assigned to the placebo.

a. Generate a 95% CI for the difference in proportions of participants reporting a reduction of symptoms between the experimental and placebo groups.

b. Estimate the RR(relative risk) for reduction in symptoms between groups.

c. Estimate the OR(odds ratio) for reduction in symptoms between groups.

d. Generate a 95% CI for the RR(relative risk).