Chapter 11, Problem 45CE

Instructions: You may use Excel, MegaStat, Minitab, JMP, or another computer package of your choice. Attach appropriate copies of the output or capture the screens, tables, and relevant graphs and include them in a written report. Try to state your conclusions succinctly in language that would be clear to a decision maker who is a nonstatistician. Exercises marked * are based on optional material. Answer the following questions, or those your instructor assigns.

1. a. Choose an appropriate ANOVA model. State the hypotheses to be tested.
2. b. Display the data visually (e.g., dot plots or line plots by factor). What do the displays show?
3. c. Do the ANOVA calculations using the computer.
4. d. State the decision rule for α = .05 and make the decision. Interpret the p-value.
5. e. In your judgment, are the observed differences in treatment means (if any) large enough to be of practical importance?
6. f. Given the nature of the data, would more data collection be practical?
7. g. Perform Tukey multiple comparison tests and discuss the results.
8. h. Perform a test for homogeneity of variances. Explain fully.

To assess the effects of instructor and student gender on student course scores, an experiment was conducted in 11 sections of managerial accounting classes ranging in size from 25 to 66 students. The factors were instructor gender (M, F) and student gender (M, F). There were 11 instructors (7 male, 4 female). Steps were taken to eliminate subjectivity in grading, such as common exams and sharing exam grading responsibility among all instructors so no one instructor could influence exam grades unduly. (a) What type of ANOVA is this? (b) What conclusions can you draw? (c) Discuss sample size and raise any questions you think may be important.