Question

Ages of 50 people in a village are given in a grouped frequency table given below.

Ages	No. of People
1 - 10	10
11 - 20	8
21 - 30	15
31 - 40	8
41 - 50	9

If the age of a person is 30, he should be included in ___________.

• A. 1st class interval
• B. 2nd class interval
• C. In both 1st and 2nd class interval
• D. 3rd class interval

Answer 1

The correct option is D 3rd class interval

There are 4 classes given in the table:

1st class: 1 - 10
2nd class: 11 - 20
3rd class: 21 - 30
4th class: 31 - 40
5th class: 41 - 50

In this case, the type of class interval is inclusive so lower and upper limit of a class interval belongs to that class interval. In the case of exclusive class interval, the upper limit is not included in the class.

So a person age 30 will belong to the 3rd class interval (21 - 30).