16 points The Etruscan civilization is a powerful civilization of ancient Italy. Here is a sample of head sizes (maximum measurement across the top of the skull in mm) of 15 Etruscans 126, 132, 140, 141, 141, 142,, 144, 145, 147, 148, 149, 150, 150, 155, 158 a. Find the sample mean and the sample SD. b. Estimate the mean head size using a 90% confidence interval. State any assumptions you are making. c. Conduct the following test: Ho: M = 146 against the alternative Ha: |