Do students at various universities differ in how sociable they are? Twenty-five students were randomly selected from each of three universities in a region and were asked to report on the amount of time they spent socializing each day with other students. The result for University X was a mean of 5 hours and an estimated population variance of 2 hours; for University Y, M = 4, S2 = 1.5; and for University Z, M = 6, S2 = 2.5. Using the 5 steps of hypothesis testing listed below, what should you conclude? (Refer to page 319 in the text for steps to complete this problem).
Step 1 (Restate the Question as a research hypothesis and null hypothesis about the populations)
Population 1:
Population 2:
Population 3:
Research Hypothesis:
Null Hypothesis:
Step 2 (Determine the characteristics of the comparison distribution)
df between:
What distribution?:
Step 3 (Using the .05 level, determine the cutoff sample score on the comparison distribution at which the null hypothesis should be rejected)
Probability:
Degrees of freedom:
Cutoff score:
Step 4 (Determine your sample's score on the comparison distribution)
Between groups population variance estimate
Within groups population variance estimate
Step 5 (Decide whether to reject the null hypothesis)
(a) Figure the effect size for the study