| Class size |
Frequency |
Cumulative frequency |
| 0 - 10 |
3 |
3 |
| 10 - 20 |
10 |
13 |
| 20 - 30 |
20 |
33 |
| 30 - 40 |
7 |
40 |
| 40 - 50 |
6 |
46 |
| 50 - 60 |
4 |
50 |
|
n = 50 |
|
\(n = 50\)
\(\frac n2 = 50\)
Cumulative frequency which is just greater than n/2 or 25 is 33 which is of class 20 - 30.
\(\therefore \) Median class = 20 - 30
l = lower limit of median class = 20
f = frequency of median class = 20
c.f. = cumulative frequency just before median class = 13
h = class interval = 30 - 20 = 10
\(\therefore \) Median = \(l + \frac{\frac n2 - cf}{f} \times h\)
\(= 20 + \frac{25 - 13}{20} \times 10\)
\(= 20 + \frac{12}2\)
\(= 20 + 6\)
\(= 26\)
Hence, median of the data set = 26.
