Gilbert Wants to Make Generalizations About the Class Attendance Rate

Gilbert wants to make generalizations about the class attendance rate in his district. He randomly samples four schools and collects data on the attendance rate of 50 classes (one class represents one observation) . Which ANOVA model is most appropriate for analysis of these data?

A) One-factor random-effects model
B) Two-factor random-effects model
C) Two-factor mixed-effects model
D) One-factor repeated measures design
E) Two-factor split-plot design