Score:
Week 2
Testing means - T-tests
Q3
In questions 2 and 3, be sure to include the null and alternate hypotheses you will be testing.
Ho
Female
Male
Female
In the first 3 questions use alpha = 0.05 in making your decisions on rejecting or not rejecting the null hypothesis.
45
34
1.017
1.096
45
41
0.870
1.025
<1 point>
1
Below are 2 one-sample t-tests comparing male and female average salaries to the overall sample mean.
45
23
1.157
1.000
(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)
45
22
0.979
0.956
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?
45
23
1.134
1.000
Males
Females
45
42
1.149
1.050
Ho: Mean salary = 45
Ho: Mean salary = 45
45
24
1.052
1.043
Ha: Mean salary =/= 45
Ha: Mean salary =/= 45
45
24
1.175
1.043
45
69
1.043
1.210
Note: While the results both below are actually from Excel's t-Test: Two-Sample Assuming Unequal Variances,
45
36
1.134
1.161
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.
45
34
1.043
1.096
Male
Ho
Female
Ho
45
57
1.000
1.187
Mean
52
45
Mean
38
45
45
23
1.074
1.000
Variance
316
0
Variance
334.6666667
0
45
50
1.020
1.041
Observations
25
25
Observations
25
25
45
24
0.903
1.043
Hypothesized Mean Difference
0
Hypothesized Mean Difference
0
45
75
1.122
1.119
df
24
df
24
45
24
0.903
1.043
t Stat
1.968903827
t Stat
-1.913206357
45
24
0.982
1.043
P(T<=t) one-tail
0.03030785
P(T<=t) one-tail
0.033862118
45
23
1.086
1.000
t Critical one-tail
1.71088208
t Critical one-tail
1.71088208
45
22
1.075
0.956
P(T<=t) two-tail
0.060615701
P(T<=t) two-tail
0.067724237
45
35
1.052
1.129
t Critical two-tail
2.063898562
t Critical two-tail
2.063898562
45
24
1.140
1.043
Conclusion: Do not reject Ho; mean equals 45
Conclusion: Do not reject Ho; mean equals 45
45
77
1.087
1.149
Is this a 1 or 2 tail test?
Is this a 1 or 2 tail test?
- why?
- why?
P-value is:
P-value is:
45
55
1.052
1.145
Is P-value > 0.05?
Is P-value > 0.05?
45
65
1.157
1.140
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 pop.
2. Q3
In questions 2 and 3, be sure to include the null and alternate
hypotheses you will be testing.
Ho
Female
Male
Female
In the first 3 questions use alpha = 0.05 in making your
decisions on rejecting or not rejecting the null hypothesis.
4. 45
23
1.157
1.000
(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)
45
22
0.979
0.956
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?
8. Note: While the results both below are actually from Excel's t-
Test: Two-Sample Assuming Unequal Variances,
45
36
1.134
1.161
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.
45
34
1.043
1.096
24. <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.)
44. b.
Since the one and two sample t-test results provided different
outcomes, which is the proper/correct apporach to comparing
salary equality? Why?
45.
46. <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.)
89. <2 points>
5
If the salary and compa mean tests in questions 2 and 3 provide
different results about male and female salary equality,
90. 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?