Question

Find the median of the following frequency distribution:

Class	10-20	20-30	30-40	40-50	50-60	60-70	70-80	80-90
Frequency	9	11	15	24	19	9	8	5

Answer 1

Class	Frequency	Cummulative frequency
10-20	9	9
20-30	11	20
30-40	15	35
40-50	24	59
50-60	19	78
60-70	9	87
70-80	8	95
8-900	5	100
	100

median of given distribution

$N=100$

$\frac{N}{2}=50$

Class frequency to $59$ is $40-50$

$l=40,F=35,f=24,h=10$

Median $l+\frac{(\frac{N}{2}-F)}{P}\times h=40+\left(\frac{50-35}{24}\right)\times 10\Rightarrow 40+\frac{25}{4}=46.25$