7. The distribution below gives the weights of 30 students of a class. Find the median weight of the students.
Class |
Number of students |
Cumulative Frequency |
40-45 | 2 | 2 |
45-50 | 3 | 5 |
50-55 | 8 | 13 |
55-60 | 6 | 19 |
60-65 | 6 | 25 |
65-70 | 3 | 28 |
70-75 | 2 | 30 |
MEDIAN:
Median class = 55-60; Lower limit, l = 55;
Cumulative frequency of preceding class, c.f. = 13; f = 6; h = 5
Thus, median weight of the student is 56.67 kg