Irwin and colleagues (2004) conducted research on adherence to an exercise regimen. We give an overview of the study in exercise 12.38. Here are the data:

<5 sessions: 155, 120, 130

5–8 sessions: 199, 160, 184

9–12 sessions: 230, 214, 195, 209

a. What is the independent variable in this study? What are its levels?

b. What is the dependent variable in this study?

c. Use the six steps of hypothesis testing to conduct a one-way between-groups ANOVA.

d. What is R for these data? How large is this effect according to Cohen’s conventions?

e. What is for these data? How large is this effect according to Cohen’s conventions?

Exercise 12.38

Irwin and colleagues (2004) conducted a study on adherence to an exercise program. Participants were asked to attend a monthly group education program to help them change their exercise behavior. Attendance was taken and participants were divided into three categories: those who attended fewer than 5 sessions, those who attended between 5 and 8 sessions, and those who attended between 9 and 12 sessions. The researchers assessed the number of minutes of exercise per week for all participants. Assume that you plan to do Bonferroni post hoc comparisons if the ANOVA is statistically significant.