An advertisement by Schering Corp. in 1999 for the allergy drug Claritin mentioned that in a pediatric randomized clinical trial, symptoms of nervousness were shown by 4 of 188 patients on loratadine (Claritin), 2 of 262 patients taking placebo, and 2 of 170 patients on choropheniramine. In each part below, explain which method you used, and why.

a. Is there inferential evidence that nervousness depends on drug?

b. For the Claritin and placebo groups, construct and interpret a 95% confidence interval for the (i) odds ratio and (ii) difference of proportions suffering nervousness.