11. Prepare a frequency distribution from the Following Data.
Mid
5
10
15
20
25
Points
30
Frequency / 40
60
20
10
30
12. From the following data relating to wages of 30 workers, prepare frequency
Answers
Question 11:
Make a frequency curve of the following data:
Class-interval 20−40 40−60 60−80 80−100 100−120 120−140 140−160
Frequency 3 7 11 15 13 6 2
ANSWER:
Class Interval Frequency
20 − 40
40 − 60
60 − 80
80 − 100
100 − 120
120 − 140
140 − 160
3
7
11
15
13
6
2
Page No 7.40:
Question 12:
From the following information, construct, less than and more than ogive.
Daily wages (in ₹) 60−90 90−120 120−150 150−180 180−210
No. of Workers 11 14 25 12 8
ANSWER:
For constructing less than ogive, first the given frequency distribution must be converted into less than cumulative frequency distribution as follows.
Daily Wages No. of workers
Less than 90
Less than 120
Less than 150
Less than 180
Less than 210 11
25
50
62
70
We now plot the cumulative frequencies against the upper limit of class intervals. The curve obtained on joining the points so plotted is known as less than ogive.
For constructing more than ogive, first the given frequency distribution must be converted into more than cumulative frequency distribution as follows.
Daily Wages No. of workers
More than 60
More than 90
More than 120
More than 150
More than 180 70
70 − 11 = 59
59 − 14 = 45
45 − 25 = 20
20 − 12 = 8
We now plot the cumulative frequencies against the lower limit of class intervals. The curve obtained on joining the points so plotted is known as more than ogive.