NOW WORK A random sample of n measurements was selected from a population with unknown mean / and known standard deviation o. Calculate a 95% confidence interval for / for each of the following situations: a. n = 75, x = 28, 62 = 12 b. n = 200, x = 102, of = 22[Data Set: L06028] The following sample of 16 measurements was selected from a population that is approximately normally distributed: 91 80 99 110 95 106 78 121 106 100 97 82 100 83 115 104 a. Construct an 80% confidence interval for the population mean. b. Construct a 95% confidence interval for the population mean and compare the width of this interval with that of part a. c. Carefully interpret each of the confidence intervals and explain why the 80% confidence interval is narrower