Question 1Brieflyand concisely discuss in your own words the following:
a. Explain the three characteristics of a correlation.
b. Describe an example of each of the four uses of correlation.
c. Compare Pearson correlation with Point‐biserial correlation and give an example of each.
d. Give an example of a linear relationship and identify the two constants y‐ intercept and slope of the line.
Question 2A sports psychologist wanted to find out whether there is a relationship betweendrinking coffee and speed in running a 5 k run. He recorded the time (in minutes) of5 coffee drinkers competing in the marathon as follows: 27, 25, 23, 24, 26, and 5 non‐coffee drinkers also competing in the same marathon as follows: 28, 24, 13, 21, 20.
Convert these data into a form suitable for the point‐biserial correlation, and assign a score of 0 to the non‐coffee drinkers and a 1 to the coffee drinkers.
A) Compute the point biserial correlation
B) compute the coefficient of determination (r2) and describe how much of the variability in marathon speed is determined by its association with drinking coffee.
Question 3Aneducational psychologist would like to know the relationship between thenumber of hours per week that students study for a course and their performance inthe test.
No. of Hours of Study

Test Score

8

84

10

90

7

85

6

71

5

73

4

68

9

86

12

92

6

70

8

80

a. Compute the Pearson correlation of the data below.
b. Determine the significance of the correlation at α .05, two‐tailed by referring to Table B.6(←)in the Appendix of your textbook. State whether the correlation is significant.
Question 4Theeducational psychologist in Question 2 above wanted to confirm the Pearson correlation that he obtained by ranking the number of hours of study and the test scores. He then computed the Spearman correlation. Using the data in Question 2 above:
A) Do as the psychologist did
B) show whether his conclusion regarding the significance of the Spearman correlation is similar to his conclusion regarding the Pearson correlation. (After computing the Spearman correlation, refer to Table B.7 in the Appendix of your textbook.) →
Question 5A human resources manager wishes to determine whether there is a relationship between having a bachelor’s degree and being promoted within the first two years of employment in their company. Use the data in the table below to:
A) Compute the phi‐coefficient, and
B) compute the coefficient of determination (r2). What conclusion can you give regarding the relationship between having a bachelor’s degree and being promoted? (Hint: Substitute 1 to Yes and 0 to No to all 20 employees.)
Degree

Promotion

Degree

Promotion

No

Yes

No

No

No

Yes

No

No

No

Yes

No

No

Yes

Yes

No

No

Yes

Yes

No

No

Yes

Yes

Yes

No

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

Question 6 An I/O psychologist would like to predict the salary of employees based on years of employment in the company. He took a small sample of employees, asked them their years of service and their annual salary (in thousands of dollars) and then computed the linear regression. Find the regression equation for the following data:
Years Employed

Annual Salary

5

42

1

28

5

48

1

35

3

27

a. What is the regression equation?
b. Based on the regression equation, predict the annual salary of an employee with 2 years ofe mployment.
c. Does the regression equation account for a significant portion of the variance of annual salary? (Hint: Compute F‐ratio.)
Question 7Briefly and concisely discuss in your own words the following:
a. Compare parametric tests with nonparametric tests.
b. Explain when you would use a χ2test compared to when you would use a t test.
c. Discuss two assumptions χ2 for tests.
d. Compare the Mann‐Whitney U‐Test with the Wilcoxon Signed‐ranks Test.
Question 8A specialist on consumer psychology wanted to determine whether there is a difference in clients’ preferences among four flavours of a new energy drink that is just being introduced in the market. Conduct a goodness of fit chi‐square test at α .05, using the 5 steps of hypothesis testing, of the following observations that the psychologist collected from n = 120 clients:
Flavour 1

Flavour 2

Flavour 3

Flavour 4

32

28

44

16

Question 9 Is there a relationship between colour preference of office rooms and gender? Anv ergonomist was asked by the HR vice president of a company during the planning stage of redesigning their offices for greater well‐being and productivity of their employees. The ergonomist conducted a survey and the results are shown below. Conduct a chi‐square test of independence at α .01, using the 5 steps of hypothesis testing.
Gender

Blue

Green

Beige

Yellow

Female

18

25

20

23

Male

32

18

20

16

Question 10 A cognitive psychologist is testing the influence of the use of imagery on the memory of students. He collected the following data on a memory test after the learning situation where imagery was used on half of the participants. Rank the scores and perform a Mann‐Whitney test at α .05, using the 5 steps of hypothesis testing. (Hint: Use the formula to generate the U value for each sample.)
With Imagery

Without Imagery


10

12

6

7

9

14

8

5

9

11

10

7

8

12

8

6

Question 11 A dietician is helping 10 people lose weight. Although she has shown a lot of evidence that the diet she prescribed in the past has always been effective, the drawback is she must keep her clients motivated to maintain the diet after they have reached their ideal weight. Otherwise, if the clients revert to their old eating habits, they will regain the weight they lost. And so, she requested a hypnotherapist to train her clients selfhypnosis in order to keep their motivation to stay on course with their ideal weight. The data below show the weight of the clients before they learned selfhypnosis and their weight a year after they learned selfhypnosis during which time they maintained their diet. Convert the weights into ranks and conduct a Wilcoxon test at α .01, onetailed test, to evaluate the effectiveness of the diet combined with selfhypnosis, using the five steps of hypothesis testing.
Client

Weight before SelfHypnosis

Weight after SelfHypnosis

1

125

120

2

117

115

3

140

136

4

110

109

5

135

136

6

121

118

7

136

130

8

123

118

9

114

108

10

138

138
