Families USA, a monthly magazine that discusses related to health and health costs, surveyed 30 of its subscribers. It found that the annual health insurance premiums for a family with coverage through an employer averaged $16,469. The standard deviation of the sample was $2,000.
(a) What is the population mean? What is the best estimate of the population mean?
(b) Based on this sample information, develop a 95% confidence interval for the population mean yearly premium.
(c) How large of a sample is needed to assess the population mean with an allowable error of $600 at 99% confidence?