Suppose that we have the following three sets of observations. sample set sample size mean value standard deviation set A 122 1.75 1.71 set B 34 1.71 1.64 set C 21 1.52 1.72 (1). Assuming that all the samples in the three sets are realizations of the same random variable X that is normally distributed, calculate the 95% confidence interval for each of the means. (2). Assuming that all the samples in the three sets are realizations of the same random variable X that is normally distributed, be