Rerun the analysis in Exercise 13.29 but treat both variables as fixed and crossed. Show that the SS school (code) in Ex13-31 is the sum of SS school and SS school *code in this analysis. (Hint: If...

Rerun the analysis in Exercise 13.29 but treat both variables as fixed and crossed. Show that the SS_school(code) in Ex13-31 is the sum of SS_school
and SS_school*code in this analysis. (Hint: If you run this using SPSS you will have to have both sets of schools numbered 1–7.)

An educational researcher wanted to test the hypothesis that schools that implemented strict dress codes produced students with higher academic performance. She randomly selected 7 schools in the state with dress codes and 7 schools that had no dress code. She then randomly selected 10 students within each school and noted their performance on a standardized test. The results follow.