Ashford 3: - Week 2 - Assignment

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Ashford 3: - Week 2 - Assignment

Problem Set Week Two

In the Week Two Assignment sheet, complete the problems below and submit your work in an Excel document. Be sure to show all of your work and clearly label all calculations. All statistical calculations will use the Employee Salary Data Set and Week 1 assignment sheet.

See comments at the right of the data set.

ID

Salary

Compa

Midpoint

Age

Performance Rating

Service

Gender

Raise

Degree

Gender1

Grade

8

23

1.000

23

32

90

9

1

5.8

0

F

A

The ongoing question that the weekly assignments will focus on is: Are males and females paid the same for equal work (under the Equal Pay Act)?

10

22

0.956

23

30

80

7

1

4.7

0

F

A

Note: to simplfy the analysis, we will assume that jobs within each grade comprise equal work.

11

23

1.000

23

41

100

19

1

4.8

0

F

A

14

24

1.043

23

32

90

12

1

6

0

F

A

The column labels in the table mean:

15

24

1.043

23

32

80

8

1

4.9

0

F

A

ID – Employee sample number

Salary – Salary in thousands

23

23

1.000

23

36

65

6

1

3.3

1

F

A

Age – Age in years

Performance Rating – Appraisal rating (Employee evaluation score)

26

24

1.043

23

22

95

2

1

6.2

1

F

A

Service – Years of service (rounded)

Gender: 0 = male, 1 = female

31

24

1.043

23

29

60

4

1

3.9

0

F

A

Midpoint – salary grade midpoint

Raise – percent of last raise

35

24

1.043

23

23

90

4

1

5.3

1

F

A

Grade – job/pay grade

Degree (0= BS\BA 1 = MS)

36

23

1.000

23

27

75

3

1

4.3

1

F

A

Gender1 (Male or Female)

Compa - salary divided by midpoint

37

22

0.956

23

22

95

2

1

6.2

1

F

A

42

24

1.043

23

32

100

8

1

5.7

0

F

A

3

34

1.096

31

30

75

5

1

3.6

0

F

B

18

36

1.161

31

31

80

11

1

5.6

1

F

B

20

34

1.096

31

44

70

16

1

4.8

1

F

B

39

35

1.129

31

27

90

6

1

5.5

1

F

B

7

41

1.025

40

32

100

8

1

5.7

0

F

C

13

42

1.050

40

30

100

2

1

4.7

1

F

C

22

57

1.187

48

48

65

6

1

3.8

0

F

D

24

50

1.041

48

30

75

9

1

3.8

1

F

D

45

55

1.145

48

36

95

8

1

5.2

0

F

D

17

69

1.210

57

27

55

3

1

3

0

F

E

48

65

1.140

57

34

90

11

1

5.3

1

F

E

28

75

1.119

67

44

95

9

1

4.4

1

F

F

43

77

1.149

67

42

95

20

1

5.5

1

F

F

19

24

1.043

23

32

85

1

0

4.6

1

M

A

25

24

1.043

23

41

70

4

0

4

0

M

A

40

25

1.086

23

24

90

2

0

6.3

0

M

A

2

27

0.870

31

52

80

7

0

3.9

0

M

B

32

28

0.903

31

25

95

4

0

5.6

0

M

B

34

28

0.903

31

26

80

2

0

4.9

1

M

B

16

47

1.175

40

44

90

4

0

5.7

0

M

C

27

40

1.000

40

35

80

7

0

3.9

1

M

C

41

43

1.075

40

25

80

5

0

4.3

0

M

C

5

47

0.979

48

36

90

16

0

5.7

1

M

D

30

49

1.020

48

45

90

18

0

4.3

0

M

D

1

58

1.017

57

34

85

8

0

5.7

0

M

E

4

66

1.157

57

42

100

16

0

5.5

1

M

E

12

60

1.052

57

52

95

22

0

4.5

0

M

E

33

64

1.122

57

35

90

9

0

5.5

1

M

E

38

56

0.982

57

45

95

11

0

4.5

0

M

E

44

60

1.052

57

45

90

16

0

5.2

1

M

E

46

65

1.140

57

39

75

20

0

3.9

1

M

E

47

62

1.087

57

37

95

5

0

5.5

1

M

E

49

60

1.052

57

41

95

21

0

6.6

0

M

E

50

66

1.157

57

38

80

12

0

4.6

0

M

E

6

76

1.134

67

36

70

12

0

4.5

1

M

F

9

77

1.149

67

49

100

10

0

4

1

M

F

21

76

1.134

67

43

95

13

0

6.3

1

M

F

29

72

1.074

67

52

95

5

0

5.4

0

M

F

Score:

Week 2

Testing means - T-tests

In questions 2 and 3, be sure to include the null and alternate hypotheses you will be testing.

In the first 3 questions use alpha = 0.05 in making your decisions on rejecting or not rejecting the null hypothesis.

<1 point>

1

Below are 2 one-sample t-tests comparing male and female average salaries to the overall sample mean.

(Note: a one-sample t-test in Excel can be performed by selecting the 2-sample unequal variance t-test and making the second variable = Ho value -- see column S)

Based on our sample, how do you interpret the results and what do these results suggest about the population means for male and female average salaries?

Males

Females

Ho: Mean salary = 45

Ho: Mean salary = 45

Ha: Mean salary =/= 45

Ha: Mean salary =/= 45

Note: While the results both below are actually from Excel's t-Test: Two-Sample Assuming Unequal Variances,

having no variance in the Ho variable makes the calculations default to the one-sample t-test outcome - we are tricking Excel into doing a one sample test for us.

 

Male

Ho

 

Female

Ho

Mean

52

45

Mean

38

45

Variance

316

0

Variance

334.667

0

Observations

25

25

Observations

25

25

Hypothesized Mean Difference

0

Hypothesized Mean Difference

0

df

24

df

24

t Stat

1.96890383

t Stat

-1.9132

P(T<=t) one-tail

0.03030785

P(T<=t) one-tail

0.03386

t Critical one-tail

1.71088208

t Critical one-tail

1.71088

P(T<=t) two-tail

0.0606157

P(T<=t) two-tail

0.06772

t Critical two-tail

2.06389856

 

t Critical two-tail

2.0639

 

Conclusion: Do not reject Ho; mean equals 45

Conclusion: Do not reject Ho; mean equals 45

Is this a 1 or 2 tail test?

Is this a 1 or 2 tail test?

- why?

- why?

P-value is:

P-value is:

Is P-value > 0.05?

Is P-value > 0.05?

Why do we not reject Ho?

Why do we not reject Ho?

Interpretation:

<1 point>

2

Based on our sample data set, perform a 2-sample t-test to see if the population male and female average salaries could be equal to each other.

(Since we have not yet covered testing for variance equality, assume the data sets have statistically equal variances.)

Ho:

Ha:

Test to use:

Place B43 in Outcome range box.

P-value is:

Is P-value < 0.05?

Reject or do not reject Ho:

If the null hypothesis was rejected, what is the effect size value:

Meaning of effect size measure:

Interpretation:

b.

Since the one and two sample t-test results provided different outcomes, which is the proper/correct apporach to comparing salary equality? Why?

<1 point>

3

Based on our sample data set, can the male and female compas in the population be equal to each other? (Another 2-sample t-test.)

Ho:

Ha:

Statistical test to use:

Place B75 in Outcome range box.

What is the p-value:

Is P-value < 0.05?

Reject or do not reject Ho:

If the null hypothesis was rejected, what is the effect size value:

Meaning of effect size measure:

Interpretation:

<1 point>

4

Since performance is often a factor in pay levels, is the average Performance Rating the same for both genders?

Ho:

Ha:

Test to use:

Place B106 in Outcome range box.

What is the p-value:

Is P-value < 0.05?

Do we REJ or Not reject the null?

If the null hypothesis was rejected, what is the effect size value:

Meaning of effect size measure:

Interpretation:

<2 points>

5

If the salary and compa mean tests in questions 2 and 3 provide different results about male and female salary equality,

which would be more appropriate to use in answering the question about salary equity? Why?

What are your conclusions about equal pay at this point?

(Note: Questions 1- 4 have additional elements to respond to below the analysis results and included in the Week Two Assignment sheet are 2 one-sample t-tests comparing male and female average salaries to the overall sample mean.)