A teacher figures that final grades in the chemistry department are distributed as: A, 25%;
F, 5%. At the end of a randomly selected semester, the following number of grades were recorded. Find the critical value
to determine if the grade distribution for the department is different than expected. Use α = 0.01.
◦ 7.779
◦ 9.488
◦ 13.277
◦ 15.086