the sampling distribution of the sample mean that will be used to create the desired confidence interval for population mean?A.Approximately normal with a mean of $50.50B.A standard normal distributionC.A t distribution with 15 degrees of freedomD.A t distribution with 14 degrees of freedom
14.1 pt(s).In estimating the population mean with the population standard deviation unknown, if the sample size is 12, there will be 6 degrees of freedom.
15.1 pt(s).Given a sample mean of 2.1 and a sample standard deviation of 0.7 from a sample of 10 data points, a 90% confidence interval will have a width of 2.36.
16.1 pt(s).The head librarian at the Vancouver Public Library has asked her assistant for an interval estimate of the mean number of books checked out each day. The assistant provides the following interval estimate: from 740 to 920 books per day. If the head librarian knows that the population standard deviation is 150 books checked out per day, approximately how large a sample did her assistant use to determine the interval estimate?
17.The head librarian at the Vancouver Public Library has asked her assistant for an interval estimate of the