Cumulative frequency curve:
A curve that represents the cumulative frequency distribution of grouped data is called an ogive or cumulative frequency curve.
The two types of Ogives are more than type ogive and less than type ogive. An ogive representing a cumulative frequency distribution of ‘more than’ type is called a more than ogive. An ogive representing a cumulative frequency distribution of ‘less than’ type is called a less than ogive.
Ogives can be used to find the median of a grouped data. The median of grouped data can be obtained graphically by plotting the Ogives of the less than type and more than type and locate the point of intersection of both the Ogives. The x-coordinate of the point of intersection of two Ogives gives the median of the grouped data.