A study of 10 American adults from a simple random sample yields a mean height of 67.2 inches and a standard deviation of s = 5 inches. A. What is the 95% confidence interval for the average height of all American adults? [3 points] B. Explain why you use the test statistic you selected. [2 points] C. Interpret your 95% confidence interval. [2 points] D. If the sample sized increased to 20, and no other factors changed, what would happen to your confidence interval? Why? Do not simply recalculate the confidence interval