In: Statistics and Probability
The following three independent random samples are obtained from three normally distributed populations with equal variances. The dependent variable is starting hourly wage, and the groups are the types of position (internship, co-op, work study). Round answers to 4 decimal places.
Internship | Co-op | Work Study |
---|---|---|
9.25 | 10.5 | 10.75 |
9.5 | 9.75 | 10 |
10.75 | 11 | 10.5 |
12 | 10.75 | 11.25 |
10.25 | 10.25 | 9.75 |
10.75 | 9.25 | 10.25 |
10 | 11.5 | 9 |
9.75 | 9.75 | 10 |
10.25 | 9.5 | 11.25 |
12.75 | 11 | 10.75 |
10 | 11.5 | 8.75 |
8.25 | 10 | 10.25 |
9 | 9.5 | 9 |
10 | 11.75 | 8.75 |
10 | 9.5 | 8.75 |
11.5 | 13.5 | 9.75 |
10.25 | 11.25 | 10.75 |
11 | 11.75 | 11.25 |
9.75 | 11.25 | 10.75 |
10 | 11.5 | 11 |
Use Excel to conduct a single-factor ANOVA to determine if the
group means are equal using α=0.05
Group means:
Internship:
Co-op:
Work Study:
Fill in the summary table for the ANOVA test:
SS | df | MS | |
Between | |||
Within | |||
Total |
From this table, obtain the necessary statistics for the ANOVA:
ANOVA summary statistics:
Test Statistic =
p-value =
Conclusion:
Null hypothesis
Alternative hypothesis
The means are not equal.
Source of Variation | SS | df | MS |
Between Groups | 4.1896 | 2 | 2.0948 |
Within Groups | 56.3719 | 57 | 0.9890 |
Total | 60.5615 | 59 |
Test Statistic =2.1181
p-value =0.1296
P value is =0.1296 >0.05
Therefore, we fail to reject H0 at
Conclusion:We do not have enough evidence to reject the null
hypothesis at that the
population means are all equal.
We can directly use here one way anova by Excel.
Step 1 ) Enter data in Excel.
Step 2) Data >>Data analysis >> One way anova >>Select data >>click on label in first row >>ok