In Section 8-9, we gave a sample size formula for confidence interval estimation of a mean. If the confidence level is 95%, then because the z-multiple is about 2, this formula is essentially

However, this formula is based on the assumption that the sample size n will be small relative to the population size N. If this is not the case, the appropriate formula turns out to be

Save your time - order a paper!

Get your paper written from scratch within the tight deadline. Our service is a reliable solution to all your troubles. Place an order on any task and we will take care of it. You won’t have to worry about the quality and deadlines

Order Paper Now

(This is based on the same idea as the finite population correction from the previous chapter.) Now suppose you want to find a 95% confidence interval for a population mean. Based on preliminary (or historical) data, you believe that the population standard deviation is approximately 15. You want the confidence interval to have length 4. That is, you want the confidence interval to be of the form X ± 2. What sample size is required if N = 400? if N = 800? if N = 10,000? if N = 100,000,000? How would you summarize these findings in words?

"Looking for a Similar Assignment? Get Expert Help at an Amazing Discount!"