2. (30 points) Professor Declan MacManus is testing whether a new teaching method has any effect on his students' test scores. He plans to give the same exam to two different classes. In one class (14 students), he uses his regular method and in the other class ( 15 students), he uses the new method. The exam scores are: Regular Method Class New Method Class 81 79 91 86 94 84 91 85 89 84 95 80 89 86 84 85 78 83 86 83 89 81 88 85 a. Please test the normality assumption using the test. b. Please test the homoscedasticity assumption using the test. c. Regardless of whether the tests in (a) and (b) are violated, please perform a six-step test