Answer:
Explanation:
By the figure, it would mean:
67, 67, 68
72, 72, 73, 76, 76, 77, 78
80, 81, 83, 83, 85, 85, 85, 87, 88
91, 91, 93, 95, 99
a) 2 students
b) 9 students
c) 2 students
Explanation : 5 students (90s) - 3 students (60s) = 2 students
d) 81
Explanation : (67 + 67 + 68 + 72 + 72 + 73 + 76 + 76 + 77 + 78 + 80 + 81 + 83 + 83 + 85 + 85 + 85 + 87 + 88 + 91 + 91 + 93 + 95 + 99) ÷ 24 = 81.33