Students are randomly assigned to receive individual tuition from teacher A or from teacher B. The marks of students attending teacher A are compared with the marks of students attending teacher B on a standard test. The marks for the A group are 75, 84, 63,42, 91, 87, 69, 73, 78, and 56. The marks for the B group are 89, 80, 47, 68, 96, 92, 78, 74, 61, 83, 79, and 88.

a. Perform an appropriate statistical test to determine whether there is convincing evidence that the effectiveness of the two teachers is different.

b. Would your conclusions change if instead of individual tuition the scenario involved two classes for the two groups of students taught by teachers A and B? POLI967