THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION

Essay

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
The U.S.Senate has 100 members.62 senators' offices obtained certain information from the individuals responsible for managing correspondence.Of these,40 specified a minimum number of letters that must be received on an issue before a form letter in response is created.
-A college has 3,400 undergraduate students and 600 graduate students.Researchers are interested in the amount of money spent in a year on textbooks by these students.Initially,simple random samples of 25 undergraduate students and 25 graduate students were taken.The sample standard deviations for the amounts spent were $45 and $64,respectively.A 95% confidence interval for the overall population mean that extends $6 on each side of the sample point estimate is required.Estimate the total number of additional sample observations needed to achieve this goal under proportional allocation.