This is in Statistics. Solve the problem below.

6. (10 points) A sample of 15 measurements of the breaking strengths of cotton threads gave a mean of 7.38 oz and a standard deviation of 1.28 oz. Assume normal distribution, find (a) 95%, (b) 99% confidence limits for the actual mean breaking strength. Note: Xtt- where c = a , and a = 1 _ yoconfidence n 2 100