Standard Article

Random Variable

  1. Asit P. Basu

Published Online: 15 JUL 2005

DOI: 10.1002/0470011815.b2a15129

Encyclopedia of Biostatistics

Encyclopedia of Biostatistics

How to Cite

Basu, A. P. 2005. Random Variable. Encyclopedia of Biostatistics. 6.

Author Information

  1. University of Missouri, Columbia, MO, USA

Publication History

  1. Published Online: 15 JUL 2005


Random variables are used to describe the uncertain outcomes of a study. Formally, a random variable is a function assigning a real value to each outcome of the sample space, which is the set of all possible outcomes. Related topics described here include the distinction between continuous and discrete random variables, the probability density function and cumulative distribution function, a bivariate distribution, conditional and marginal probability, and independence.


  • sample space;
  • continuous;
  • discrete;
  • density function;
  • cumulative distribution;
  • bivariate;
  • conditional;
  • marginal;
  • independence