When using the given sample results and the claim given in Exercise 1, the 95% confidence interval of 10.00732, 0.1592 is obtained. 

Data in Exercise 1

In a randomized clinical trial of adults with an acute sore throat, 288 were treated with the drug dexamethasone and 102 of them experienced complete resolution; 277 were treated with a placebo and 75 of them experienced complete resolution (based on data from “Effect of Oral Dexamethasone Without Immediate Antibiotics vs Placebo on Acute Sore Throat in Adults,” by Hayward et al., Journal of the American Medical Association). Identify the null and alternative hypotheses corresponding to the claim that patients treated with dexamethasone and patients given a placebo have the same rate of complete resolution.

a. Express the confidence interval in the format of an inequality that uses the symbol < .

b. What feature of the confidence interval is a basis for deciding whether there is a significant difference between the success rate in the treatment group and the success rate in the placebo group?