Editing Multimodal distribution (section)

===Mathematical===

A bimodal distribution commonly arises as a mixture of two different [[unimodal]] distributions (i.e. distributions having only one mode).  In other words, the bimodally distributed random variable X is defined as <math> Y </math> with probability <math> \alpha </math> or <math> Z </math> with probability <math> (1-\alpha), </math> where ''Y'' and ''Z'' are unimodal random variables and <math>0 < \alpha < 1</math> is a mixture coefficient.

Mixtures with two distinct components need not be bimodal and two component mixtures of unimodal component densities can have more than two modes. There is no immediate connection between the number of components in a mixture and the number of modes of the resulting density.