Solved by verified expert:A researcher conducted a mail survey of the alumni of University X to determine the proportion of alumni who made financial donations to University X after graduation. She mailed out questionnaires to a simple random sample of 600 alumni. 150 alumni responded to the mail survey. Out of these 150 alumni, 90 made financial donations to University X after graduation. The researcher then randomly selected 150 out of the 450 alumni who did not respond to the mail survey, and contacted them by telephone. All of these 150 alumni cooperated. Out of these 150 alumni, 30 made financial donations to University X after graduation. Let π denote the proportion of alumni of University X who made financial donations to University X after graduation. Construct a 99% confidence interval for π. (Show work)
