A study was conducted to determine if patients recovering from knee surgery should receive physical therapy two or three times per week.

A study was conducted to determine if patients recovering from knee surgery should receive physical therapy two or three times per week. Suppose represents the proportion of patients who showed improvement after one month of therapy three times a week and represents the proportion of patients who showed improvement after one month of therapy twice a week. A 98% confidence interval for is Give an interpretation of this confidence interval.