Chapter 11.4, Problem 20SE

Instructions for Exercises 11.17 through 11.20: Use the table of critical values from Table 11.5 and the sample variances from your previous ANOVA (see Exercises 11.5–11.7). (a) State the degrees of freedom for Hartley’s test. (b) Find Hartley’s critical value at the 5 percent level of significance. (c) Calculate Hartley’s test statistic. (d) What is your conclusion about group variances? Optional challenge: (e*) If you have access to Minitab or another software package, perform Levene’s test for equal group variances at the 5 percent level of significance. Does Levene’s test agree with Hartley’s test?

11.20 Refer to Exercise 11.8. Are the population variances the same for weekly sales (4 stores)?