A sample of size 50 is used to test the following hypothesis: Ho: u = 17.5 vs. Ha: u # 17.5 and the level of significance is .01. Give the critical values, the rejection and non-rejection regions, the computed test statistic, and your conclusion if a) x bar = 21.5 and s = 5.5 (sigma is unknown)

b) x bar = 21.5 and sigma = 5.0