A completely randomized design was conducted to compare the effects of five stimuli on reaction time. Twenty-seven people were employed in the experiment, which was conducted using a completely randomized design. Regardless of the results of the ANOVA, it is desired to compare stimuli A and D. The reaction times (in seconds) were as shown in the accompanying table.
|
Stimulus |
|
A |
B |
C |
D |
E |
|
0.8 |
0.7 |
1.2 |
1 |
0.6 |
|
0.6 |
0.8 |
1 |
0.9 |
0.4 |
|
0.6 |
0.5 |
0.9 |
0.9 |
0.4 |
|
0.5 |
0.5 |
1.2 |
1.1 |
0.7 |
|
|
0.6 |
1.3 |
0.7 |
0.3 |
|
|
0.9 |
0.8 |
|
|
|
|
0.7 |
|
|
|
| Total |
2.5 |
4.7 |
6.4 |
4.6 |
2.4 |
| Mean |
0.625 |
0.671 |
1.067 |
0.92 |
0.48 |
a Conduct an ANOVA and test for a difference in mean reaction times due to the five stimuli. Give bounds for the p-value.
b Compare stimuli A and D to see if there is a difference in mean reaction times. What can be said about the attained significance level?