Question

The mode of the following data is 33 and the total frequency is 100:
0 - 10
Class
10 - 20
20-30
30 - 40
40 - 50
50-60
7
12
Frequency
х
28
y
9
Find the missing frequencies x and y.​

Answer 1

Answer

Class intervals Frequency

10-20 7

20-30 12

30-40 20

40-50 11

50-60 8

Here maximum frequency is 20 ,the class corresponding to this 30-40

So modal class is 30-40

Now lower limit of modal class (l)=30

Frequency (f1) of modal class =20

frequency (f0) of preceding the modal class =12

frequency (f2) of the class succeeding the modal class=11

Class size=10

Mod=l+[

2f1−f0−f2

f1−f0

]×h

Mod =30+[

2×20−12−11

20−12

]×10=30+

17

8

×10=30+4.705=34.705