As an owner of a local accounting firm, you would like to know the mean tax refund people get in your town. This way you can advertise how customers can benefit from your services to get a better refund. You take a random sample of 16 tax refunds last year from people you surveyed by mail (who did not file with you), and find a sample average of $576.41 and a standard deviation of $150.39

a) Construct a 95% confidence interval for the true mean tax refund.

b) Interpret the confidence interval in a.

c) Are you assuming anything that is not directly given to you in the problem to construct the confidence interval in a? Explain.