Q12 of 37 Page 14

Compute the mean of the following data, using direct method: [CBSE 2005]


Class

0 - 100

100 - 200

200 - 300

300 - 400

400 - 500

Frequency

6

9

15

12

8

For equal class intervals, we will solve by finding mid points of these classes using direct method.


CLASS

MID - POINT(xi)

FREQUENCY(fi)

fixi

0 - 100

50

6

300

100 - 200

150

9

1350

200 - 300

250

15

3750

300 - 400

350

12

4200

400 - 500

450

8

3600

TOTAL

  

50

13200

We have got


Σfi = 50 & Σfixi = 13200


∵ mean is given by



⇒


⇒


Thus, mean is 264

More from this chapter

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10

For a certain distribution, mode and median were found to be 1000 and 1250 respectively. Find mean for this distribution using an empirical relation.[CBSE 2014]

 11

Find the mode of the given data: [CBSE 2015]


Class interval

0 - 20

20 - 40

40 - 60

60 - 80

Frequency

15

6

18

10
13

If the mean of the following frequency distribution is 54, find the value of p. [CBSE 2006]


Class

0 - 20

20 - 40

40 - 60

60 - 80

80 - 100

Frequency

7

p

10

9

13
14

Compute the mean of the following data: [CBSE 2013]


Class

1 - 3

3 - 5

5 - 7

7 - 9

Frequency

12

22

27

19