Find the mean deviation about the mean for the following data : Mark 0-10 10-20 20-30 30-40 40-50 50-60 Number of Students 6 8 14 16 4 2

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

Mark

0-10

10-20

20-30

30-40

40-50

50-60

Number of Students

6

8

14

16

4

2

we make the following table from the given data:

Mark	Number of Students f_i	Mid-points x_i	f_ix_i
0-10	6	5	30
10-20	8	15	120
20-30	14	25	350
30-40	16	35	560
40-50	4	45	180
50-60	2	55	110
	50		1350

Therefore,

Mark	Number of Students f_i	Mid-points x_i	f_ix_i
0-10	6	5	30	22	132
10-20	8	15	120	12	96
20-30	14	25	350	2	28
30-40	16	35	560	8	128
40-50	4	45	180	18	72
50-60	2	55	110	28	56
	50		1350		512

Thus, the required mean deviation about the mean is

1