Please follow all directions!!!!

Name________________________________________________________

Statistics for Psychology-Take home Exam 2

This exam should be completed on your own. Working together with anyone to complete these questions is cheating and is in violation of Temple University’s Academic Honesty Policy.

If you cheat on this exam you will receive zero points.

Some of the following questions will require hand calculations and some will require you to use Jamovi.

Hand calculations

For the questions that will require hand calculations, be sure to show ALL your work.

If no work is shown, even a correct answer will result in zero points.

Numbers have been provided for each question to get you started with the hand calculations. You are given numbers that will allow you to conduct a couple of different statistical tests. However, only one statistical test is the correct one to conduct. So you have to know what statistical test is appropriate and, thus, what numbers to use. The numbers to conduct the correct statistical test are valid but the others are simply made up. Be sure to look at symbols to know what these numbers are representing.

Jamovi

For the questions that will require Jamovi, you will need to turn in a Jamovi output. Generate only what is best/appropriate. Points will be taken off for unnecessary/inappropriate numbers.

Once you have produced the appropriate output for each question, copy and paste the appropriate output into your document.

Jamovi cannot conduct a z-test. So whenever you choose a z-test you have to conduct this test by hand.
One-sample, paired samples, and independent samples t-tests can all be conducted in Jamovi. So when you choose any of these t-tests read the instructions for that specific question to determine if you will do this test by hand or using Jamovi.

Please submit your entire exam as one document. Ensure that everything is organized, easy to find, and easy to read. Points will be taken off otherwise.

There 8 questions. Be sure to answer all questions. Also, be aware that questions have multiple parts.

This take-home exam is to be submitted to Canvas by 1pm on Monday November 16th. Late exams will have points deducted. Please see the syllabus for the late submission policy.

1. In a study to test the effects of science fiction movies on people's belief in the supernatural, seven people completed a measure of belief in the supernatural before and after watching a popular science fiction movie. Participants' scores are listed below with high scores indicating higher levels of belief. Using the .01 significance level, test the experimenter's assumption that the participants' belief in the supernatural would change after watching the movie.

Belief-in-Supernatural Scores

Participant Before After

A 6 7

B 3 5

C 6 6

D 6 2

E 1 9

F 3 7

G 2 3

A) What is the appropriate test for this data?

B) Conduct the appropriate hypothesis test by hand. Follow the five steps of hypothesis testing and provide a drawing.

C) Give an interpretation of this data (one sentence conclusion of the hypothesis test that should be free of statistical jargon) and, when appropriate, report the statistics in APA format.

D) Explain why the test you chose is the most appropriate.

Mbefore = 3.86

Mafter = 5.57

SSbefore= 26.86

SSafter = 35.71

Mdifference = 1.71

SSdifference = 81.43

Difference = After – before

2. A swimming school claimed that after taking lessons from their instructors the average seven-year-old would be able to swim across an Olympic-sized pool in significantly less time than the average. The average time is 3 minutes. To test this claim, a psychologist arranged for eight randomly selected seven-year-old children to take lessons at the school and recorded how long it took each child to swim across a pool at the end of the lessons. The times (in seconds) were 92, 111, 120, 75, 132, 84, 73, and 114. Use the .05 significance level to determine if the students did swim significantly faster than the average.

A) What is the appropriate test for this data?

B) Conduct the appropriate hypothesis test by hand. Follow the five steps of hypothesis testing and provide a drawing.

C) Give an interpretation of this data (one sentence conclusion of the hypothesis test that should be free of statistical jargon) and, when appropriate, report the statistics in APA format.

D) Explain how you found the mean and standard deviation of the comparison distribution. Do not just list equations. In your explanation, be sure to use the names of the concepts. For example, if you are calculating variance for the distribution of means call it that. Do not simply say “that number”.

M = 100.13

SS = 3414.88

SD = 20.66

3. An industrial psychologist consulting with a chain of music stores knows that the average number of complaints management receives each month throughout the industry is μ = 4. Twelve of the chain's stores were randomly selected to record complaints for one month; they received 7, 6, 10, 6, 1, 9, 1, 1, 1, 10, 6, and 2 complaints. Use the .05 significance level to determine if the number of complaints received by the chain is different from the industry average.

A) What is the appropriate test for this data?

B) Conduct the appropriate hypothesis test. Only hand calculate if you choose a z-test and then follow the five steps of hypothesis testing and provide a drawing. Otherwise, use Jamovi.

C) Give an interpretation of this data (one sentence conclusion of the hypothesis test that should be free of statistical jargon) and, when appropriate, report the statistics in APA format.

D) Explain why the test you chose is the most appropriate.

M = 5

SS = 146

SD = 12.16

4. A team of cognitive psychologists studying the effects of sleep deprivation on short-term memory decay had nine participants stay in a sleep lab for two days. Five participants were randomly assigned to a condition in which they were not permitted to sleep during that period, while the other four participants were allowed to sleep when they wanted to. At the end of the two days, the participants completed a short-term memory task that yielded the results in the table that follows. Using the .05 significance level, did sleep deprivation reduce short-term memory?

Mean Number of Letters Remembered

Sleep Deprived Normal Sleep

5 9

8 9

5 11

9 7

A) What is the appropriate test for this data?

B) Conduct the appropriate hypothesis test by hand. Follow the five steps of hypothesis testing and provide a drawing.

C) Give an interpretation of this data (one sentence conclusion of the hypothesis test that should be free of statistical jargon) and, when appropriate, report the statistics in APA format.

Msleep deprived = 6.6

Mnormal sleep= 9

SSsleep deprived = 13.20

SSnormal sleep= 8

Mdifference = -0.60

SSdifference = 91.20

Difference = Sleep deprived – normal sleep

5. A health psychologist conducted an experiment in which some participants watched a film that included a person being injured because of not wearing a seat belt while other participants watched a film that did not include this. They then reported how important they thought it was to wear seat belts on a scale from 0 to10 (0 = not important at all, 10 = extremely important). Use the .01 significance level to determine if seeing a movie where a person gets injured due to not wearing a seat belt affects attitudes towards seat belt usage.

Film with injury due to not wearing a seat belt

1 10 3 3 0 2 1 5 7 10 8

5 7 10 2 6 1 8 8 3 5 10

Film without injury due to not wearing a seat belt

7 1 6 3 9 8 2 3 1 4 0 9 3

9 0 7 2 7 6 6 9 9 1 6 4 5

A) What is the appropriate test for this data?

B) Conduct the appropriate hypothesis test. Only hand calculate if you choose a z-test and then follow the five steps of hypothesis testing and provide a drawing. Otherwise, use Jamovi.

C) Give an interpretation of this data (one sentence conclusion of the hypothesis test that should be free of statistical jargon) and, when appropriate, report the statistics in APA format.

D) Explain how you came to your conclusion about the null.

MFilm with injury = 5.23

MFilm w/o injury = 4.88

SSFilm with injury= 237.86

SSFilm w/o injury = 234.65

Mdifference = -0.46

SSdifference = 526.46

Difference = Film with injury – Film w/o injury

6. A school psychologist interested in the effect of a program designed to reduce adjustment problems in newly transferred students. She knew from her years of working at the school that the average score on a scale of adjustment difficulties for transfer students was μ = 48 with σ = 10. On this scale a lower score means fewer adjustment problems. After starting the program, the psychologist tested 50 students and found their mean to be 52. Using the .05 level of significance, was this a significant decrease?

A) What is the appropriate test for this data?

B) Conduct the appropriate hypothesis test. Only hand calculate if you choose a z-test and then follow the five steps of hypothesis testing and provide a drawing. Otherwise, use Jamovi.

C) Give an interpretation of this data (one sentence conclusion of the hypothesis test that should be free of statistical jargon) and, when appropriate, report the statistics in APA format.

D) Explain how you came to your conclusion about the null.

SD = 8.90

SS = 35.67

7. A psychology professor of a large class became curious as to whether the students who turned in tests first scored differently from the overall mean on the test. The overall characteristics are μ = 75 with σ = 10; the scores were approximately normally distributed. The mean score for the first 20 students to turn in tests was 78. Use the .01 significance level to determine if there was a significant difference.

A) What is the appropriate test for this data?

B) Conduct the appropriate hypothesis test. Only hand calculate if you choose a z-test and then follow the five steps of hypothesis testing and provide a drawing. Otherwise, use Jamovi.

C) Give an interpretation of this data (one sentence conclusion of the hypothesis test that should be free of statistical jargon) and, when appropriate, report the statistics in APA format.

SD = 7.14

SS = 14.17

8. An organizational psychologist is hired as a consultant to a company planning to open a coffee house for college students. The company wants to know if their customers will drink more coffee if the coffee house is decorated in a Paris theme or in a San Francisco theme. The psychologist sets up two similar rooms with the two themes. Eight students spend an afternoon in each room, drinking all the coffee they like. The order in which they sit in the rooms is rotated so that half spend their first afternoon in the Paris room and half in the San Francisco room. The amount of coffee each participant drinks in each room is shown below. Use the .05 significance level to determine if there a significant difference between the numbers of cups of coffee consumed in the two rooms.

Participant Paris San Francisco

A 8.5 8.4

B 4.3 4.6

C 2.0 1.7

D 7.8 7.3

E 6.0 7.2

F 6.1 7.4

G 3.3 3.0

H 3.5 3.5

A) What is the appropriate test for this data?

B) Conduct the appropriate hypothesis test. Only hand calculate if you choose a z-test and then follow the five steps of hypothesis testing and provide a drawing. Otherwise, use Jamovi.

C) Give an interpretation of this data (one sentence conclusion of the hypothesis test that should be free of statistical jargon) and, when appropriate, report the statistics in APA format.

D) Explain why the test you chose is the most appropriate.

MParis = 5.19

MSan Francisco = 5.39

SSParis= 36.65

SSSan Francisco = 43.55

Mdifference = -0.20

SSdifference = 3.34

Difference = Paris – San Francisco