100 people are given a standard antibiotic to treat an infection and another 100 are given a new antibiotic. In the ?rst group, 90 people recover; in the second group, 85 people recover. Let p1 be the probability of recovery under the standard treatment and let p2 be the probability of recovery under the new treatment. We are interested in estimating θ = p1 - p2. Provide an estimate, standard error, an 80 percent con?dence interval, and a 95 percent con?dence interval for θ.