Question

economics
12) Calculate simple arithmetic mean from following data
Marks:
10
20
30
40
50
60
70
80
no. of students
2
5
9
10
12
7
3
2​

Answer 1

Answer:

Marks

Midpoint(x

i

)

No. of students(f

i

)

Deviation(d

i

)

u

i

u

i

f

i

0-10

5

8

-30

-3

-24

10-20

15

15

-20

-2

-30

20-30

25

22

-10

-1

-22

30-40

35

20

0

0

0

40-50

45

10

10

1

10

50-60

55

5

20

2

10

N=∑f

i

=80, h=10

A=35,d

i

=x

i

−A , u

i

=

h

d

i

Mean=A+h(

N

∑u

i

f

i

)

=35+10(

80

−56

)

Mean=28