Problem 8: 10 points = [5 + 5] Payroll specialists selected n = 9 technicians and analyzed how their wages have changed in one year. Paired records, (X, Y), indicate daily wages for years 1 and 2, respectively. These records were summarized as follows: X = 164, Y = 175 and the sample standard deviation for D = Y - X was found as S = 15. 1. At the significance level, a = 0.05, do you have enough evidence that the population average increased, or M ( Y ) > M (X ) ? 2. Estimate the average population change (u(Y) - u(X)) in wages with C = 95% confidence. Show critical values in either case and calculations needed! Solution