Homework 8 Partially completed
Topic 8 Homework
PriviteraStats2 17.E.023.
A professor tests whether the loudness of noise during an exam (low, medium, and high) is independent of exam grades (pass, fail). The following table shows the observed frequencies for this test.
|
|
Noise Level |
|
|||
|
|
Low |
Medium |
High |
|
|
|
Exam |
Pass |
21 |
16 |
8 |
45 |
|
|
Fail |
8 |
7 |
11 |
26 |
|
|
29 |
23 |
19 |
N = 71 |
(a) Conduct a chi-square test for independence at a 0.05 level of significance. (Round your answer to two decimal places.)
Retain the null hypothesis. Reject the null hypothesis.
(b) Compute effect size using Cramer's V. (Round your answer to two decimal places.) V = X
PriviteraStats2 18.E.019.
A community psychologist selects a sample of 16 local police officers to test whether their physical endurance is better than the median score of 72. She measures their physical endurance on a 100-point physical endurance rating scale.
|
Performance Scores |
|||
|
89 |
57 |
78 |
74 |
|
58 |
95 |
81 |
65 |
|
93 |
85 |
94 |
91 |
|
84 |
87 |
88 |
90 |
Based on the data given above, compute the one-sample sign test at a 0.05 level of significance. x = X State whether to retain or reject the null hypothesis.
Retain the null hypothesis. Reject the null hypothesis.
PriviteraStats2 18.E.023.
Practitioners measured spiritual well-being (SWB) in a sample of 16 adults who were alcoholic before and following treatment for alcoholism.
|
Change in SWB Following Treatment |
|
|
+14 |
+20 |
|
+5 |
−4 |
|
−7 |
+15 |
|
+13 |
+11 |
|
+12 |
−8 |
|
+9 |
+6 |
|
+10 |
−1 |
|
−3 |
−2 |
Use the normal approximation for the Wilcoxon signed-ranks T test to analyze the data above. (Round your answer to two decimal places.) z = X State whether to retain or reject the null hypothesis. (Assume alpha equal to 0.05.)
Retain the null hypothesis. Reject the null hypothesis.
PriviteraStats2 18.E.025.
A professor has a teaching assistant record the amount of time (in minutes) that a sample of 16 students engaged in an active discussion. The assistant observed 8 students in a class who used a slide show presentation and 8 students in a class who did not use a slide show presentation.
|
With Microsoft PowerPoint |
Without Microsoft PowerPoint |
|
19 |
7 |
|
8 |
6 |
|
13 |
18 |
|
21 |
11 |
|
12 |
23 |
|
14 |
10 |
|
9 |
5 |
|
15 |
4 |
Use the normal approximation for the Mann-Whitney U test to analyze the data above. (Round your answer to two decimal places.) z = X State whether to retain or reject the null hypothesis. (Assume alpha equal to 0.05.)
Retain the null hypothesis. Reject the null hypothesis.
PriviteraStats2 18.E.027.
A statistics instructor measured student attitudes toward a statistics course prior to lectures, at the midterm, and after the final exam. Attitudes were measured on a 16-point scale, with higher scores indicating more positive attitudes toward the statistics course.
|
Student |
Prior to Lectures |
At the Midterm |
After the Final |
|
A |
6 |
5 |
10 |
|
B |
4 |
9 |
14 |
|
C |
8 |
7 |
13 |
|
D |
12 |
11 |
16 |
|
E |
5 |
6 |
10 |
Based on the results shown in the table, test whether or not attitudes differed using the Friedman test at a 0.05 level of significance. (Round your answer to two decimal places.)
Retain the null hypothesis. Reject the null hypothesis.
0.19
3
-0.42
1.37
2.75
5.104