Question

The median class for the following data is
$$\begin{array}{cccccc}\text{Marks}& \text{Below 10}& \text{Below 20}& \text{Below 30}& \text{Below 40}& \text{Below 50}\\ \text{No. of students}& 5& 10& 23& 31& 40\end{array}$$

• A. 10-20
• B. 20-30
• C. 30-40
• D. 40-50

Answer 1

The correct option is B

20-30

The given table can be re-written as follows and the cumulative frequency is given.
The given table can be written as:
$$\begin{array}{cccccc}\text{Marks}& 0-10& 10-20& 20-30& 30-40& 40-50\\ \text{Cumulative Frequency}& 5& 10& 23& 31& 40\end{array}$$
Since there are a total of 40 observations, the median class is the one whose cumulative frequency is closest to and greater than 20. The class interval 20-30 is the required answer.