The distribution below gives the weights of 30 students of a class. Find the median weight of the students
Weight (in kg) | 40 - 45 | 45 - 50 | 50 - 55 | 55 – 60 | 60 - 65 | 65 - 70 | 70 - 75 |
Number of students | 2 | 3 | 8 | 6 | 6 | 3 | 2 |
The cumulative frequency of the given data can be calculated as:
Class interval | frequency | 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 |
As per the question,
N= 30
Hence,
Median class = 55-60
Lower limit, l = 55
cf = 13
f = 6
h = 5
Now,
Median can be calculated as:
= 56.67
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