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:

Xbar = 164, Ybar = 175

and the sample standard deviation for D = Y X was found as S = 15.

1. At the significance level, = 0.05, do you have enough evidence that the population average increased, or (Y ) > (X)?

2. Estimate the average population change ((Y ) (X)) in wages with C = 95% confidence. Show critical values in either case and calculations needed!