The runs scored by two teams A and B on the first 60 balls in a cricket match are given below:

Solution:

It can be observed that the class intervals of the given data are not continuous. There is a gap of 1 in between them. Therefore, $\frac{1}{2}=0.5$ has to be added to the upper class limits and $0.5$ has to be subtracted from the lower class limits.

Also, class mark of each interval can be found by using the following formula.

Class mark $=\frac{\text { Upper class limit }+\text { Lower class limit }}{2}$

Continuous data with class mark of each class interval can be represented as follows.



By taking class marks on x-axis and runs scored on y-axis, a frequency polygon can be constructed as follows.