Ogive
An ogive (also known as a cumulative frequency curve) is a graph used in statistics to represent the cumulative frequencies for the classes in a frequency distribution. It helps in estimating the median, quartiles, and percentiles of a dataset.
Example
If plotting the cumulative frequency of students' test scores, the x-axis represents the upper class boundaries of the scores, and the y-axis represents the cumulative frequency. The median score can be found by locating $\frac{N}{2}$ on the y-axis and finding the corresponding x-value on the curve.