Aetna, a major health insurance company, would like to estimate the average wait time for a patient seeking emergency room services. A random sample of 33 emergency room patients had an average wait time of 222 minutes with a sample standard deviation of 76 minutes. Determine the confidence interval to estimate the average wait time for the following confidence levels:

a. 90%

b. 95%

c. 99%

d. How does the confidence level impact the precision of the estimate?

e. What assumptions need to be made in conjunction with this analysis?

AppendixLO1