Question

What is the cumulative frequency of the number of students in a class 8-10?

Class	2-4	4-6	6-8	8-10	10-12
No. of students.	20	12	15	17	19

Answer 1

Hint: : In this problem, we have to find the cumulative frequency of the number of students in a class from 8-10 from the given table. We can form a cumulative frequency distribution table and find the cumulative frequency by adding the terms respectively for the given question to find the required answer.

Complete step by step answer:
Here we have to find the cumulative frequency for the given number of students from the class 8-10.
We should know that the cumulative frequency is calculated by adding each frequency from a frequency distribution table to the sum of its predecessors. The last value will always be equal to the total for all observations, since all frequencies will already have been added to the previous total.
We can now form the table by adding them one by one, we get

Class	Frequencies (No. of students)	Cumulative frequency	Total
2-4	20	20	20
4-6	12	20+12	32
6-8	15	32+15	47
8-10	17	47+17	64
10-12	19	64+19	73

Here we can see that the cumulative frequency of the number of students in a class 8-10 is 64.
Therefore, the answer is 64.

Note: We should always remember how to form a cumulative frequency table as it is calculated by adding each frequency from a frequency distribution table to the sum of its predecessors. The last value will always be equal to the total for all observations, since all frequencies will already have been added to the previous total.