L. F. Gilbreath, the vice president of human resources for a major U. S. airline, wants to compare four programs for training employees to perform a certain task. Twenty employees are randomly assigned to the training programs, with five in each program. At the end of the training period, the number of times each employee can perform the task in a five-minutes period is recorded as follows: Program 1 Program 2 Program 3 Program 4
9 10 12 9
12 6 14 8
14 9 11 11
11 9 13 7
13 10 11 8
If L. F. conducts an analysis of variance [ANOVA] test to compare the training programs,
State your conclusion (meaning, describe what the decision means in this problem)
a. The programs are equal in terms of task time
b. None of the programs differ in terms of mean task time
c. At least two programs differ in terms of mean task time
d. All programs differ in terms of mean task time