According to the graph, 52% of 1000 students, who do not participate in the activities held after school, receive grades of A and B. In this case, 52% of 1000 is 520.

There are 395 out of 500 students who participate in after-school activities and get grades of A or B. In this case, the percentage of this value is 79%, which is almost equivalent to 3/4.

Majority of the students, who participate in after-school activities, make grades of A and B. The same thing happens for the students who do not participate in the said activities.