Below are test scores of 20 students under two teachers and two kinds of textbooks used in teaching English. Apply the F-test level of significance. TEACHERS Test if there is significant difference: Textbooks A B Total 1. among the scores under different teachers; 2. Among the scores under different textbooks AWNGU 3. Do scores vary under different teachers 00 0 w 10 00 using different groups Assume Normal distribution Sub Total B