Families USA, a monthly magazine that discusses issues related to health and health costs, surveyed 18 of its subscribers. It found that the annual health insurance premiums for a family with coverage through an employer averaged $10,450. The standard deviation of the sample was $985.
(a) Based on this sample information, develop a 90 percent confidence interval for the population mean yearly premium. (Round up your answer to the next whole number. Omit the "$" sign in your response.)
Confidence interval for the population mean yearly premium is between $_____ and $______.
(b) How large a sample is needed to find the population mean within $264 at 90 percent confidence? (Round up your answer to the next whole number.)© BrainMass Inc. brainmass.com June 4, 2020, 12:47 am ad1c9bdddf
This solution shows how to develop a 90 percent confidence interval for the population mean yearly premium, formatted in an attached Word document.