Calculate median from the following series:
Class Interval
10-20
20-40
40-70
70-120
120-140
Frequency
4
10
26
8
2
| C.I. | frequency (f) | c.f |
| 10-20 | 4 | 4 |
| 20-40 | 10 | 14 |
| 40-70 | 26 | 40 |
| 70-120 | 8 | 48 |
| 120-140 | 2 | 50 |
| N=50 |
Median = L + [{n/2-c.f.}/26]*h
where,
L= lower limit of median class.
n=total no.of solution
c.f. = cumulative frequency of preceding class
h= height or width of meadian class
Median = 40 + [{(50/2)-14}/26]*30
= 52.69