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. What should you conclude? Use the .05 level. (a) Use the steps of hypothesis testing, (b) figure the effect size for the study; and (c) explain your answers to parts (a) and (b) to someone who has never had a course in statistics.

Answer 1

You might try a one-way ANOVA on this data. Use the appropriate table to compare your test statistic to the critical value from the table at .05 level of significance. If the test statistic exceeds the critical value from the table, reject the null and conclude a difference. If the test statistic does not exceed the critical value from the table, do not reject the null (you cannot conclude a difference in this case).