The following grouped data represent the body weights of 64 students of a school:
Weight (kg)
40–50
50–60
60–70
70–80
80–90
90–100
Number of students
12
x
20
y
8
4
The mode of the distribution is 66.5 kg.
(a) Verify that the class 60–70 kg is the modal class.
(b) Using the given information and the fact that the total number of students is 64, find the missing frequencies x and y.
(c) After finding x and y, write the complete frequency distribution.