For the following distribution draw a 'less than type' ogive and from the curve find the median.

Marks obtained	Less than 20	Less than 30	Less than 40	Less than 50	Less than 60	Less than 70	Less than 80	Less than 90	Less than 100
Number of students	2	7	17	40	60	82	85	90	100

Lets plot a graph of ‘less than ogive’, taking upper limits of the class intervals on x - axis and cumulative frequencies on y - axis.

As we have N = 100 by the frequency table.

N/2 = 100/2 = 50

Mark 50 on y - axis and the corresponding point on x - axis would be the median.

The corresponding point on x - axis is 55.

Hence, median is 55.