Score:
Week 5
Correlation and Regression
<1 point>
1.
Create a correlation table for the variables in our data set. (Use analysis ToolPak or StatPlus:mac LE function Correlation.)
a.
Reviewing the data levels from week 1, what variables can be used in a Pearson's Correlation table (which is what Excel produces)?
b. Place table here (C8):
c.
Using r = approximately .28 as the signicant r value (at p = 0.05) for a correlation between 50 values, what variables are
significantly related to Salary?
To compa?
d.
Looking at the above correlations - both significant or not - are there any surprises -by that I
mean any relationships you expected to be meaningful and are not and vice-versa?
e.
Does this help us answer our equal pay for equal work question?
<1 point>
2
Below is a regression analysis for salary being predicted/explained by the other variables in our sample (Midpoint,
age, performance rating, service, gender, and degree variables. (Note: since salary and compa are different ways of
expressing an employee’s salary, we do not want to have both used in the same regression.)
Plase interpret the findings.
Ho: The regression equation is not significant.
Ha: The regression equation is significant.
Ho: The regression coefficient for each variable is not significant
Note: technically we have one for each input variable.
Ha: The regression coefficient for each variable is significant
Listing it this way to save space.
Sal
SUMMARY OUTPUT
Regression Statistics
Multiple R
0.9915591
R Square
0.9831894
Adjusted R Square
0.9808437
Standard Error
2.6575926
Observations
50
ANOVA
df
SS
MS
F
Significance F
Regression
6
17762.3
2960.38
419.1516
1.812E-36
Residual
43
303.7003
7.0628
Total
49
18066
Coefficients
Standard Error
t Stat
P-value
Lower 95%
Upper 95%
Lower 95.0%
Upper 95.0%
Intercept
-1.749621
3.618368
-0.4835
0.631166
-9.046755
5.5475126
-9.04675504
5.54751262
Midpoint
1.2167011
0.031902
38.1383
8.66E-35
1.1523638
1.2810383
1.152363828
1.28103827
Age
-0.004628
0.065197
-0.071
0.943739
-0.136111
0.1268547
-0.13611072
0.1268547
Performace Rating
-0.056596
0.034495
-1.6407
0.108153
-0.126162
0.0129695
-0.12616237
0.01296949
Service
-0.0425
0.084337
-0.5039
0.616879
-0.212582
0.1275814
-0.2125.
2. <1 point>
1.
Create a correlation table for the variables in our data set. (Use
analysis ToolPak or StatPlus:mac LE function Correlation.)
a.
Reviewing the data levels from week 1, what variables can be
used in a Pearson's Correlation table (which is what Excel
produces)?
8. c.
Using r = approximately .28 as the signicant r value (at p =
0.05) for a correlation between 50 values, what variables are
significantly related to Salary?
10. d.
Looking at the above correlations - both significant or not - are
there any surprises -by that I
mean any relationships you expected to be meaningful and are
not and vice-versa?
12. <1 point>
2
Below is a regression analysis for salary being
predicted/explained by the other variables in our sample
(Midpoint,
age, performance rating, service, gender, and degree variables.
(Note: since salary and compa are different ways of
expressing an employee’s salary, we do not want to have both
13. used in the same regression.)
Plase interpret the findings.
14. Ho: The regression equation is not significant.
Ha: The regression equation is significant.
Ho: The regression coefficient for each variable is not
significant
15. Note: technically we have one for each input variable.
Ha: The regression coefficient for each variable is significant
Listing it this way to save space.
Sal
29. What is the value of the F statistic:
What is the p-value associated with this value:
30. Is the p-value <0.05?
Do you reject or not reject the null hypothesis:
31. What does this decision mean for our equal pay question:
32. For each of the coefficients:
Intercept
Midpoint
Age
Perf. Rat.
Service
Gender
Degree
What is the coefficient's p-value for each of the variables:
33. Is the p-value < 0.05?
Do you reject or not reject each null hypothesis:
What are the coefficients for the significant variables?
34. Using only the significant variables, what is the equation?
Salary =
Is gender a significant factor in salary:
35. If so, who gets paid more with all other things being equal?
How do we know?
36.
37. <1 point>
3
Perform a regression analysis using compa as the dependent
variable and the same independent
variables as used in question 2. Show the result, and interpret
your findings by answering the same questions.
Note: be sure to include the appropriate hypothesis statements.
62. Do we have an answer to the question of are males and females
paid equally for equal work?
If so, which gender gets paid more?
63. How do we know?
Which is the best variable to use in analyzing pay practices -
salary or compa? Why?
What is most interesting or surprising about the results we got
doing the analysis during the last 5 weeks?
64.
65. <2 points>
5
Why did the single factor tests and analysis (such as t and
single factor ANOVA tests on salary equality) not provide a
complete answer to our salary equality question?
What outcomes in your life or work might benefit from a
multiple regression examination rather than a simpler one
variable test?
66.
67. See comments at the right of the data set.
ID
Salary
Compa
Midpoint
Age
Performance Rating
Service
72. 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
73. 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= BSBA 1 = MS)