# Cumulative frequency distribution

Command: | Statistics Distribution plot Cumulative frequency distribution |

## Description

To obtain a cumulative frequency distribution plot, click **Cumulative frequency distribution** in the statistics menu.

## Required input

**Variable**: the variable of interest.**Filter**: (optionally) a data filter in order to include only a selected subgroup of cases in the graph.**Options**- Select a
**Cumulative frequency polygon**or a**Cumulative dot plot**, or both. - You also have the option to have a cumulative
**Normal distribution**curve displayed together with the cumulative distribution of the data. The cumulative Normal distribution (with Mean and Standard Deviation of the data represented in the graph) curve is displayed as a smooth line. When this option is selected the cumulative frequency distribution (Cumulative frequency polygon and/or Cumulative dot plot) is plotted using a different algorithm, allowing better visual comparison of the observed frequency distribution with the theoretical Normal distribution. **Complementary cumulative frequency**: select this option to obtain the complementary cumulative distribution function (CCDF). Whereas the Cumulative distribution function goes from 0 to 100%, the complementary cumulative distribution goes from 100% to 0.

- Select a
**Subgroups**: click the Subgroups button if you want to identify subgroups in the graph. A new dialog box is displayed in which you can select a categorical variable.

When you have completed the dialog box, click OK to obtain the graph.

## Graphs

In the next figures, some combinations of the possible selections are displayed.

Polygon and Normal distribution

Dots and Normal distribution

When you want to display the cumulative frequency distribution of several variables in one graph, see Multiple variables graphs.

## Literature

- Altman DG (1991) Practical statistics for medical research. London: Chapman and Hall.