Homework SourseA psychologist would like to examine the effects of a new dr
A psychologist would like to examine the effects of a new drug on the activity level of animals. Three samples of rats are selected with the following data. Does the data indicate any significant differences among the three groups at the 0.05 level of significance? Show all work (ANOVA)
G1 G2 G3
0 2 5
2 2 3
2 3 2
0 2 2
1 1 3
Solution
Using technology, (in Excel, Data-->Data Analysis-->Anova Single Factor), we have the summary:
As P = 0.0263 < 0.05, we reject Ho that all the means are equal.
Thus, there is significant evidence at 0.05 level that at least 2 of the means of the 3 groups here differ from each other. [CONCLUSION]
| Anova: Single Factor | ||||||
| SUMMARY | ||||||
| Groups | Count | Sum | Average | Variance | ||
| Column 1 | 5 | 5 | 1 | 1 | ||
| Column 2 | 5 | 10 | 2 | 0.5 | ||
| Column 3 | 5 | 15 | 3 | 1.5 | ||
| ANOVA | ||||||
| Source of Variation | SS | df | MS | F | P-value | F crit |
| Between Groups | 10 | 2 | 5 | 5 | 0.026336 | 3.885294 |
| Within Groups | 12 | 12 | 1 | |||
| Total | 22 | 14 |
