The median class for the following data is
MarksBelow 10Below 20Below 30Below 40Below 50No. of students510233140
20-30
The given table can be written as:
Marks0−1010−2020−3030−4040−50No. of students510233140
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.