What is the purpose of an ogive?

An ogive, also known as a cumulative histogram, is a graph that is used to determine the number of data points that are equal to or below a certain value in a data set.

An ogive is different from a frequency polygon because it is a plot of cumulative values, rather than a plot of the values themselves.

To turn a frequency polygon into an ogive, you would add up the values as you move from left to right on the y axis of the graph.

You can use ogives to determine the median and percentiles of a data set.