A sample of 15 quality control managers (N = 15) with more than 20-years of experience were asked to report their annual salary. Use the data fileUnit 3Exam Quality Salaries.xlsto complete the following:

A) Construct a 95% Confidence Interval for themeanannual salary.

B) Construct a 95% Confidence Interval for thetotalannual salary of the 15 quality control managers.

C) What size of sample is needed to ensure that you can estimate the population mean salary of all quality managers with more than 20 years of experience and be 95% confident (z = 1.96) that the mean is off by no more than $500 (B = 500), given the estimate of the population standard deviation = 3,000.

est= 3,000