Question

The class marks of a frequency distribution are given as follows: $15,20,25,..........$ The class corresponding to the class mark $20$ is:

• A. $12.5-17.5$
• B. $17.5-22.5$
• C. $18.5-21.5$
• D. $19.5-20.5$

Answer 1

The correct option is B

$17.5-22.5$

Explantion for the correct option:

Class mark:

From the given data

Difference between class marks $=5$

The classes for these class marks are listed below:

$$\begin{gathered} 2.5-7.5 \\ 7.5-12.5 \\ 12.5-17.5 \\ 17.5-22.5 \\ 22.5-27.5 \end{gathered}$$

Hence, the class corresponding to the class mark $20$ $=17.5-22.5$

Hence,option (B) is correct answer.