Classes:

25-29

30-34

35-39

40-44

45-49

50-54

55-59

Frequency:

14

22

16

6

5

3

4

Let the assumed mean (A) = 42

Class interval	Mid value (x_i)	d_i = x_i – 42	U_i =	Frequency (f_i)	f_iu_i
25-29	27	-15	-3	14	-42
30-34	32	-10	-2	22	-44
35-39	37	-5	-1	16	-16
40-44	42	0	0	6	0
45-49	47	5	1	5	5
50-54	52	10	2	3	6
55-59	57	15	3	4	12
				N = 10	∑f_iu_i = -79

We have, A = 42

h = 5

Mean = A + h *

= 42 + 5 *

= 42 -

=

= 36.357

14