1: The table below shows the numbers of parts produced by a company on each of five successive simulated days. Replication 1 2 Number of parts produced 20 17 13 15 25 4 5 (a) Calculate the sample mean and sample standard deviation for the above set of observations. Provide a rough estimate for the number of replications that would be needed to assert with 95% confidence that the sample mean you estimated differs by at most one part from the true but unknown mean. (Z0.025 = 1.96) (b) Explain why you used the particular statistical approach you did to develop the confidence interval, and any limitations on the accuracy of that approach