Question

Lessons Frequency

10-12 5

13-15 9

16-18 12

19-21 4

22-24 10

The mean for that distribution is:

- 19.11

- 18.22

- 17.38

- 16.15

The mode of this distribution is:

-23

-15

-17

-12

Answer 1

Solution:

Group	Midpoint X	Frequency f	f*x
10 to 12	11	5	55
13 to 15	14	9	126
16 to 18	17	12	204
19 to 21	20	4	80
22 to 24	23	10	230
SUM		40	695

1)

Mean   =   = = 695/40 = 17.38

Answer : 17.38

2)

We know , the mode is the observation with maximum frequency.

i.e. Mode is most repeated observation.

Observe the given frequency distribution.

Class 16 - 18 has maximum frequency.

So , mode is in between 16 and 18

Observe the given options.

So , mode is 17

Answer : 17