to predict his final exam grade and final class grade

a student wants to predict his final exam grade and final class grade with 95% confidence.

The final grade has three components: (1) an assignment (on which he scored 12 of 20);

(2) a midterm exam (on which he scored 14 of 30); and (3) a final exam which he has not yet taken.

The weight of each component is as follows: assignment 20%; midterm exam 30%; and

final exam 50%. Below in blue are scores from 30 students who took the course last term