ALLIED MAT130 MODULE 7 check your understanding

Question Points

1. Find the critical value. Assume that the test is two=tailed and that n denotes the number of pairs of data. n = 30, = 0.001.

a. 0.467

b. ±0.467

c. -0.467

d. ±0.362

2. Which of the following tests could detect some nonlinear relationships between two variables?

a. Wilcoxon signed-ranks test

b. Rank correlation test

c. Wilcoxon rank-sum test

d. Sign test

3. Which of the following distribution-free tests has no parametric counterpart?

a. Runs test

b. Sign test

c. Rank correlation test

d. Kruskal-Wallis test

4. Which of the following methods could lead to stronger evidence for the outcome of a nonparametric test?

a. Ensure that the distributions are normal

b. Increase sample size substantially

c. Take multistage random samples

d. Ensure that the populations have equal variances

5. Which of the following nonparametric tests reaches a conclusion equivalent to the Mann-Whitney U test?

a. Wilcoxon rank-sum test

b. Sign test

c. Kruskal-Wallis test

d. Wilcoxon signed-ranks test

6. The Kruskal-Wallis test statistic H has a distribution that can be approximated by which of the parametric distributions?

a. z distribution

b. t distribution

c. F distribution

d. chi-square distribution

7. When performing a rank correlation test, one alternative to using the Critical Values of Spearman's Rank Correlation Coefficient table to find critical values is to compute them using this approximation: where t is the t-score from the t Distribution table corresponding to n – 2 degrees of freedom. Use this approximation to find critical values of rs for the case where n = 17 and = 0.05.

a. ±0.311

b. ±0.480

c. ±0.482

d. ±0.411

8. Which of the following nonparametric tests reaches a conclusion equivalent to the Mann-Whitney U test?

a. Wilcoxon rank-sum test

b. Sign test

c. Kurskal-Wallis test

d. Wilcoxon signed-ranks test

9. Find the critical value. Assume that the test is two-tailed and that n denotes the number of pairs of data. n = 60, = 0.05

a. 0.255

b. ±0.253

c. -0.255

d. ±0.255

10.

The following scatterplot shows the percentage of the vote a candidate received in the 2004 senatorial elections according to the voter's income level based on an exit poll of voters conducted by CNN. The income levels 1-8 correspond to the following income classes: 1 = Under $15,000; 2 = $15-30,000; 3 = $30-50,000; 4 = $50-75,000; 5 = $75-100,000; 6 = $100-150,000; 7 = $150-200; 8 = $200,000 or more. Use the election scatterplot to find the critical values corresponding to a 0.01 significance level used to test the null hypothesis of .

a. 0.881

b. -0.881

c. -0.738 and 0.738

d. -0.881 and 0.881

11. The following scatterplot shows the percentage of the vote a candidate received in the 2004 senatorial elections according to the voter's income level based on an exit poll of voters conducted by CNN. The income levels 1-8 correspond to the following income classes: 1 = Under $15,000; 2 = $15-30,000; 3 = $30-50,000; 4 = $50-75,000; 5 = $75-100,000; 6 = $100-150,000; 7 = $150-200; 8 = $200,000 or more. Use the election scatterplot to find the value of the rank correlation coefficient rs.

a. rs = -1

b. rs = 1.97621

c. rs = -0.9762

d. rs = 0.9762

12. Find the critical value. Assume that the test is two=tailed and that n denotes the number of pairs of data. n = 7, = 0.05

a. -0.786

b. ±0.786

c. 0.786

d. ±0.714

13. When performing a rank correlation test, one alternative to using the Critical Values of Spearman's Rank Correlation Coefficient table to find critical values is to compute them using this approximation: where t is the t-score from the t Distribution table corresponding to n – 2 degrees of freedom. Use this approximation to find critical values of rs for the case where n = 40 and = 0.10.

a. ±0.264

b. ±0.304

c. ±0.312

d. ±0.202

14. Find the critical value. Assume that the test is two-tailed and that n denotes the number of pairs of data. n = 7, = 0.05

a. -0.786

b. ±0.786

c. 0.786

d. ±0.714

15.

Given below are the analysis of variance results from a Minitab display. Assume that you want to use a 0.05 significance level in testing the null hypothesis that the different samples come from populations with the same mean. Identify the value of the test statistic.

a. Reject the null hypothesis since the p-value is greater than the significance level.

b. Accept the null hypothesis since the p-value is greater than the significance level.

c. Accept the null hypothesis since the p-value is less than the significance level.

d. Reject the null hypothesis since the p-value is less than the significance level.