Question: To test whether students in a higher grade level would be less disruptive in class, a school psychologist recorded the number of documented interruptions during one day of classes from nine local high schools. The sample consisted of nine freshman, sophomore, junior, and senior high school classes. The data for each high school class are given in the table.
(a) Complete the F table.
(b) Is it necessary to compute a post hoc test? Explain.