Find the mean from the following frequency distribution of marks at a test in statistics: Marks (x): 5 10 15 20 25 30 35 40 45 50 No. of students (f): 15 50 80 76 72 45 39 9 8 6

Question

Philoid · Accepted Answer

Let the assumed mean (A) = 25

Marks (x_i)	No. of students (f_i)	u_i = x_i – A = x_i - 25	f_iu_i
5	15	-20	-300
10	50	-15	-750
15	80	-10	-800
20	76	-5	-380
25	72	0	0
30	45	5	225
35	39	10	390
40	9	15	135
45	8	20	160
50	6	25	150
	N = 400		∑f_iu_i = -1170

Mean = A +

= 25 + =

= 22.075

Marks (x):	5	10	15	20	25	30	35	40	45	50
No. of students (f):	15	50	80	76	72	45	39	9	8	6

Find the mean from the following frequency distribution of marks at a test in statistics:Marks (x):5101520253035404550No. of students (f):15508076724539986

Find the mean from the following frequency distribution of marks at a test in statistics:

Marks (x):

5

10

15

20

25

30

35

40

45

50

No. of students (f):

15

50

80

76

72

45

39

9

8

6