perform two non-parametric tests. For each hypothesis test make sure to report the following steps:

1. Identify why you choose to perform the statistical test (Sign test, Wilcoxon test, Kruskal-Wallis test).
2. Identify the null hypothesis, Ho, and the alternative hypothesis, Ha.
3. Determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed.
4. Find the critical value(s) and identify the rejection region(s).
5. Find the appropriate standardized test statistic. If convenient, use technology.
6. Decide whether to reject or fail to reject the null hypothesis.
7. Interpret the decision in the context of the original claim.

Nine students took the SAT test. Their scores are listed below. Later on, they took a test preparation course and retook the SAT. Their new scores are listed below. Use the Wilcoxon signed-rank test to test the claim that the test preparation has no effect on their scores. Use = 0.05.

Student 1 2 3 4 5 6 7 8 9

Before- 860, 820, 910, 990, 1000, 930, 870, 1180, 920

After- 880, 820, 900, 1030, 1030, 940, 860, 1220, 940

2. A medical researcher wishes to try three different techniques to lower blood pressure of patients with high blood pressure. The subjects are randomly selected and randomly assigned to one of three groups. Group 1 is given medication, Group 2 is given an exercise program, and Group 3 is assigned a special diet. At the end of six weeks, the reduction in each subject's blood pressure is recorded. Use the Kruskal-Wallis test to test the claim that there is no difference in the distributions of the blood pressures of the three populations. Use = 0.05.

Group 1 Group 2 Group 3

13 10 2

14 7 14

11 4 6

17 5 10

15 6 11

10 2 6