Given is a data

This is a more than type frequency distribution table. To find the median of this data, draw the graph of this data.

Now, total number of observations in this data, N = 40.

N/2 = 20.

In order to find the median, locate 20 on y-axis. From this point, draw a line parallel to the x-axis cutting the curve at a point. From this point, draw a perpendicular to the x-axis. The point of intersection of this perpendicular with the x-axis determines the median of the data. The median is some what approximately to 34.

 

The given data can be converted into a normal class interval frequency distribution as follows:

 

Class interval	Frequency
0 - 12	40 - 37 = 3
12 - 24	37 - 30 = 7
24 - 36	30 - 18 = 12
36 - 48	18 - 13 = 5
48 - 60	13 - 4 = 9
60 - 72	4