Find the mean deviation about the median for the following data : class 0-10 10-20 20-30 30-40 40-50 50-60 Frequency 6 8 11 18 5 2

Find the mean deviation about the median for the following data :

class

0-10

10-20

20-30

30-40

40-50

50-60

Frequency

6

8

11

18

5

2

we make the following table from the given data:

class	Frequency f_i	Cumulative frequency c.f	Mid-points x_i
0-10	6	6	5
10-20	8	14	15
20-30	11	25	25
30-40	18	43	35
40-50	5	48	45
50-60	2	50	55
	50

The class interval containing or 25th item is 20-30. Therefore, 20–30 is the median class. We know that

Here, l = 20, C = 14, f = 11, h = 10 and N = 50

Therefore,

Now,

class	Frequency f_i	Cumulative frequency c.f	Mid-points x_i	\|x_i-M\|	f_i \|x_i-M\|
0-10	6	6	5	25	150
10-20	8	14	15	15	120
20-30	11	25	25	5	55
30-40	18	43	35	5	90
40-50	5	48	45	15	75
50-60	2	50	55	25	50
	50				540

We have, and

1