A statistics instructor would like to know whether it is worthwhile to require students to do time-consuming assignments. For one section of the statistics course, assignment is assigned, collected, and graded. For another section, the same assignment is made available for students, but they are not required to turn in their homework. At the end of the semester, all students take the same final exam. The grade distributions for the two sections are as follows:

FINAL EXAM GRADE

A

B

C

D

E

Assignment

12

15

17

5

1

No Assignment

12

21

28

25

14

Do these data indicate a significant difference between the grade distributions for students with mandatory assignment versus students with no mandatory assignment? State p-value. Is it a strong effect? Which conditions contribute the most to the effect? (10 points)