Refer to Exercise 11.56. What do the normal probability plot and the residuals versus fi...

Refer to Exercise 11.56. What do the normal probability plot and the residuals versus fit plot tell you about the validity of your analysis of variance results?

Reference:

Reaction Times versus Stimuli Twenty-seven people participated in an experiment to compare the effects of five different stimuli on reaction time. The experiment was run using a completely randomized design, and, regardless of the results of the analysis of variance, the experimenters wanted to compare stimuli A and D. The results of the experiment are given here. Use the MINITAB printout to complete the exercise.

a. Conduct an analysis of variance and test for a difference in the mean reaction times due to the five stimuli.

b. Compare stimuli A and D to see if there is a difference in mean reaction times.