Score: |
Week 3 |
ANOVA and Paired T-test |
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At this point we know the following about male and female salaries. |
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a. |
Male and female overall average salaries are not equal in the population. |
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b. |
Male and female overall average compas are equal in the population, but males are a bit more spread out. |
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c. |
The male and female salary range are almost the same, as is their age and service. |
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d. |
Average performance ratings per gender are equal. |
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Let’s look at some other factors that might influence pay – education(degree) and performance ratings. |
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<1 point> |
1 |
Last week, we found that average performance ratings do not differ between males and females in the population. |
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Now we need to see if they differ among the grades. Is the average performace rating the same for all grades? |
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(Assume variances are equal across the grades for this ANOVA.) |
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You can use these columns to place grade Perf Ratings if desired. |
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A |
B |
C |
D |
E |
F |
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Null Hypothesis: |
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Alt. Hypothesis: |
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Place B17 in Outcome range box. |
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Interpretation: |
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What is the p-value: |
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Is P-value < 0.05? |
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Do we REJ or Not reject the null? |
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If the null hypothesis was rejected, what is the effect size value (eta squared): |
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Meaning of effect size measure: |
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What does that decision mean in terms of our equal pay question: |
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<1 point> |
2 |
While it appears that average salaries per each grade differ, we need to test this assumption. |
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Is the average salary the same for each of the grade levels? (Assume equal variance, and use the analysis toolpak function ANOVA.) |
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Use the input table to the right to list salaries under each grade level. |
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Null Hypothesis: |
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If desired, place salaries per grade in these columns |
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Alt. Hypothesis: |
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A |
B |
C |
D |
E |
F |
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Place B55 in Outcome range box. |
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What is the p-value: |
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Is P-value < 0.05? |
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Do you reject or not reject the null hypothesis: |
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If the null hypothesis was rejected, what is the effect size value (eta squared): |
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Meaning of effect size measure: |
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Interpretation: |
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<1 point> |
3 |
The table and analysis below demonstrate a 2-way ANOVA with replication. Please interpret the results. |
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BA |
MA |
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Ho: Average compas by gender are equal |
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Male |
1.017 |
1.157 |
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Ha: Average compas by gender are not equal |
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0.870 |
0.979 |
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Ho: Average compas are equal for each degree |
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1.052 |
1.134 |
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Ha: Average compas are not equal for each degree |
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1.175 |
1.149 |
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Ho: Interaction is not significant |
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1.043 |
1.043 |
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Ha: Interaction is significant |
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1.074 |
1.134 |
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1.020 |
1.000 |
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Perform analysis: |
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0.903 |
1.122 |
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0.982 |
0.903 |
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Anova: Two-Factor With Replication |
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1.086 |
1.052 |
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1.075 |
1.140 |
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SUMMARY |
BA |
MA |
Total |
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1.052 |
1.087 |
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Male |
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Female |
1.096 |
1.050 |
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Count |
12 |
12 |
24 |
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1.025 |
1.161 |
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Sum |
12.349 |
12.9 |
25.249 |
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1.000 |
1.096 |
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Average |
1.02908333 |
1.075 |
1.052042 |
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0.956 |
1.000 |
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Variance |
0.00668645 |
0.00652 |
0.006866 |
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1.000 |
1.041 |
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1.043 |
1.043 |
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Female |
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1.043 |
1.119 |
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Count |
12 |
12 |
24 |
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1.210 |
1.043 |
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Sum |
12.791 |
12.787 |
25.578 |
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1.187 |
1.000 |
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Average |
1.06591667 |
1.065583 |
1.06575 |
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1.043 |
0.956 |
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Variance |
0.00610245 |
0.004213 |
0.004933 |
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1.043 |
1.129 |
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1.145 |
1.149 |
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Total |
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Count |
24 |
24 |
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Sum |
25.14 |
25.687 |
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Average |
1.0475 |
1.070292 |
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Variance |
0.00647035 |
0.005156 |
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ANOVA |
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Source of Variation |
SS |
df |
MS |
F |
P-value |
F crit |
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Sample |
0.00225502 |
1 |
0.002255 |
0.383482 |
0.538939 |
4.061706 |
(This is the row variable or gender.) |
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Columns |
0.00623352 |
1 |
0.006234 |
1.060054 |
0.30883 |
4.061706 |
(This is the column variable or Degree.) |
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Interaction |
0.00641719 |
1 |
0.006417 |
1.091288 |
0.301892 |
4.061706 |
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Within |
0.25873675 |
44 |
0.00588 |
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Total |
0.27364248 |
47 |
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Interpretation: |
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For Ho: Average compas by gender are equal |
Ha: Average compas by gender are not equal |
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What is the p-value: |
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Is P-value < 0.05? |
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Do you reject or not reject the null hypothesis: |
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If the null hypothesis was rejected, what is the effect size value (eta squared): |
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Meaning of effect size measure: |
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For Ho: Average compas are equal for all degrees |
Ha: Average compas are not equal for all grades |
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What is the p-value: |
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Is P-value < 0.05? |
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Do you reject or not reject the null hypothesis: |
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If the null hypothesis was rejected, what is the effect size value (eta squared): |
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Meaning of effect size measure: |
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For: Ho: Interaction is not significant |
Ha: Interaction is significant |
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What is the p-value: |
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Is P-value < 0.05? |
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Do you reject or not reject the null hypothesis: |
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If the null hypothesis was rejected, what is the effect size value (eta squared): |
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Meaning of effect size measure: |
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What do these decisions mean in terms of our equal pay question: |
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Place data values in these columns |
<1 point> |
4 |
Many companies consider the grade midpoint to be the “market rate” – what is needed to hire a new employee. |
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Salary |
Midpoint |
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Does the company, on average, pay its existing employees at or above the market rate? |
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Null Hypothesis: |
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Alt. Hypothesis: |
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Statistical test to use: |
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Place the cursor in B160 for test. |
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