Problem # 1:
A random sample of 81 weeks showed Hootch Springs Water Company to have an average weekly sales level of $8500 with a sample standard deviation of $810. Construct the 90% and 95% interval estimates for the population mean weekly sales.
Problem # 2:
Karefree State University has an enrollment of 18,000. Researchers took a sample of 900 and found 477 students wanted a Field Hockey team. Construct the 95% and 99% Interval estimates for the population proportion.
Consider the two previous problems. At 95% confidence what sample sizes would you need:
A. to reduce the margin of error in problem #1 to 100?
B. to reduce the margin of error in problem #2 to .025?