Statistics Questions

PriviteraStats2 12.E.023.

The following is an incomplete F-table summarizing the results of a study of the variance of life satisfaction scores among unemployed, retired, part-time, and full-time employees.

(a) Complete the F-table. (Round your values for mean squares and F to two decimal places.)

X(b) Compute omega-squared

(ω2).

(Round your answer to two decimal places.) ω2 = (c) Is the decision to retain or reject the null hypothesis? (Assume alpha equal to 0.05.)

Retain the null hypothesis. Reject the null hypothesis.    

7b is wrong

PriviteraStats2 12.E.025.

Iconic memory is a type of memory that holds visual information for about half a second (0.5 seconds). To demonstrate this type of memory, participants were shown three rows of four letters for 50 milliseconds. They were then asked to recall as many letters as possible, with a 0-, 0.5-, or 1.0-second delay before responding. Researchers hypothesized that longer delays would result in poorer recall. The number of letters correctly recalled is given in the table.

(a) Complete the F-table. (Round your values for MS and F to two decimal places.)

X(b) Compute Tukey's HSD post hoc test and interpret the results. (Assume alpha equal to 0.05. Round your answer to two decimal places.)

The critical value is for each pairwise comparison.

Which of the comparisons had significant differences? (Select all that apply.)

The null hypothesis of no difference should be retained because none of the pairwise comparisons demonstrate a significant difference.

Recall following no delay was significantly different from recall following a one second delay. Recall following no delay was significantly different from recall following a half second delay. Recall following a half second delay was significantly different from recall following a one second delay.

17b is wrong

PriviteraStats2 13.E.023.

A study investigated the effects of physical fatigue on the performance of professional tennis players. Researchers measured the number of unforced errors committed by a random sample of 12 professional tennis players during the first three sets of a match. They hypothesized that increased fatigue would be associated with a greater number of errors. The following is an F-table for this hypothetical study using the one-way within-subjects ANOVA.

(a) Complete the F-table.

Make a decision to retain or reject the null hypothesis. (Assume alpha equal to 0.05.)

Retain the null hypothesis.

Reject the null hypothesis.    

(b) Estimate effect size using partial omega-squared: ωP2. (Round your answer to two decimal places.) ωP2 = X

18.

PriviteraStats2 13.E.025.

Air traffic controllers perform the vital function of regulating the traffic of passenger planes. Frequently, air traffic controllers work long hours with little sleep. Researchers wanted to test their ability to make basic decisions as they become increasingly sleep deprived. To test their abilities, a sample of 6 air traffic controllers is selected and given a decision-making skills test following 12-hour, 24-hour, and 48-hour sleep deprivation. Higher scores indicate better decision-making skills. The table lists the hypothetical results of this study.

(a) Complete the F-table. (Round your answers to two decimal places.)

(b) Compute a Bonferroni procedure and interpret the results. (Assume experiment wise alpha equal to 0.05. Select all that apply.)

There is a significant difference in decision making for the 12-hour and 24-hour sleep deprivation conditions.

X There are no significant differences between any of the groups.

There is a significant difference in decision making for the 12-hour and 48-hour sleep deprivation conditions.

There is a significant difference in decision making for the 24-hour and 48-hour sleep deprivation conditions.

19b is wrong

19.

PriviteraStats2 13.E.027.

Some studies show that people who think they are intoxicated will show signs of intoxication, even if they did not consume alcohol. To test whether this is true, researchers had a group of five adults consume nonalcoholic drinks, which they were told contained alcohol. The participants completed a standard driving test before drinking and then after one nonalcoholic drink and after five nonalcoholic drinks. A standard driving test was conducted in a school parking lot where the participants had to maneuver through traffic cones. The number of cones knocked over during each test was recorded. The following table lists the data for this hypothetical study.

(a) Complete the F-table. (Round your answers to two decimal places.)

(b) Compute a Bonferroni procedure and interpret the results. (Assume experiment wise alpha equal to 0.05. Select all that apply.)

Students knocked over significantly more cones after 5 nonalcoholic drinks compared with the driving test prior to drinking.

Students knocked over significantly more cones after 1 nonalcoholic drink compared with the driving test prior to drinking.

Students knocked over significantly more cones after 5 nonalcoholic drinks compared with the driving test after 1 nonalcoholic drink.

X There were no significant differences between any of the groups.

PriviteraStats2 13.E.031.

Wilfley and colleagues (2008) tested whether the antiobesity drug sibutramine would be an effective treatment for people with binge eating disorder. They measured the frequency of binge eating every 2 weeks for 24 weeks during treatment. The following table lists a portion of the data similar to results reported by the authors for the frequency of binge eating over the first 8 weeks of the drug treatment.

(a) Complete the F-table. (Round your answers to two decimal places.)

Make a decision to retain or reject the null hypothesis. (Assume experiment wise alpha equal to 0.05.)

Retain the null hypothesis. Reject the null hypothesis.    

(b) Use the Bonferroni procedure to make the post hoc test. In which week do we first see significant differences compared to baseline?

Week 2 is the first week where significant differences from baseline are evident.

Week 4 is the first week where significant differences from baseline are evident.    

Week 6 is the first week where significant differences from baseline are evident.

Week 8 is the first week where significant differences from baseline are evident.

XNone of the weeks are significantly different from the baseline.

27.

PriviteraStats2 14.E.023.

Seasonal affective disorder (SAD) is a type of depression during seasons with less daylight (e.g., winter months). One therapy for SAD is phototherapy, which is increased exposure to light used to improve mood. A researcher tests this therapy by exposing a sample of SAD patients to different intensities of light (low, medium, high) in a light box, either in the morning or at night (these are the times thought to be most effective for light therapy). All participants rated their mood following this therapy on a scale from 1 (poor mood) to 9 (improved mood). The hypothetical results are given in the following table.

(a) Complete the F-table and make a decision to retain or reject the null hypothesis for each hypothesis test. (Round your answers to two decimal places. Assume experiment wise alpha equal to 0.05.)

State the decision for the main effect of the time of day.

Retain the null hypothesis. Reject the null hypothesis.    

State the decision for the main effect of intensity.

Retain the null hypothesis. Reject the null hypothesis.    

State the decision for the interaction effect.

Retain the null hypothesis. Reject the null hypothesis.    

(b) Compute Tukey's HSD to analyze the significant main effect.

The critical value is for each pairwise comparison.

Summarize the results for this test using APA format.

This answer has not been graded yet.

28b is wrong

PriviteraStats2 14.E.025.

To test the relationship between gender and ratings of a promiscuous partner, a group of men and women was given a vignette describing a person of the opposite sex who was in a dating relationship with one, two, or three partners. Participants rated how positively they felt about the individual described in the vignette, with higher ratings indicating more positive feelings.

(a) Complete the F-table and make a decision to retain or reject the null hypothesis for each hypothesis test. (Assume experimentwise alpha equal to 0.05.)

State the decision for the main effect of gender.

Retain the null hypothesis. Reject the null hypothesis.    

State the decision for the main effect of promiscuity.

Retain the null hypothesis. Reject the null hypothesis.    

State the decision for the interaction effect.

Retain the null hypothesis. Reject the null hypothesis.    

X(b) Based on the results you obtained, what is the next step?

Compute simple main effect tests for the significant interaction. Compute pairwise comparisons for the promiscuity factor.      Compute pairwise comparisons for the gender factor. No further analysis is needed, because none of the effects are significant.

8.13

4.07

7.18

18.27

9.47

4

4.57

4.53

8

0.57

30.93

14

30.80

76

4

7.70

6.31

12.27

5

2.45

24.40

20

1.22

67.47

2.11

29

0.25

1

0.11

18.67

2

39

9.33

3.93

0.67

0.33

0.14

71.17

30

2.37

90.75

0.44

2.92

Time of day independently did not have a significant effect on seaso

Intensity independently have a significant effect on seasonal affecti

There is no significant interaction effect of time of day and intensity

1

1

140

70

15.2

119

76

2

38

5.70

100

15

6.67

176

17

3.67

22

2

5.5

55

11

2

121

35

60

0.33

172.1

86.06

6.63

125.7

5

25.16

129.8

10

3

12.99

427.7

17