Construct a confidence interval for mu d, the mean of the differences d for the population of paired data assume that the population of paired differences is normally distributed. Construct a 90% confidence interval for the population mean of all differences x-y X - 4.4, 5.4, 6.1, 2.8, 5.9 Y - 4.1, 4.2, 5.7, 3.5, 3.6