1. A maker of portable exercise equipment, designed for health-conscious people who travel too frequently to use a regular athletic club, wants to estimate the proportion of traveling business people who may be interested in the product. A random sample of 120 traveling business people indicates that 28 may be interested in purchasing the portable ?tness equipment. Give a 95% con?dence interval for the proportion of all traveling business people who may be interested in the product.
2. The makers of a medicated facial skin cream are interested in determining the percentage of people in a given age group who may bene?t from the ointment. A random sample of 68 people results in 42 successful treatments. Give a 99% con?dence interval for the proportion of people in the given age group who may be successfully treated with the facial cream.