random variable

American

noun

Statistics.

a quantity that takes any of a set of values with specified probabilities.

random variable British

noun

rv. statistics a quantity that may take any of a range of values, either continuous or discrete, which cannot be predicted with certainty but only described probabilistically

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of random variable

First recorded in 1935–40

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

If the random variable is discrete, such as for categorical data, then the parameter we wish to estimate is the population proportion.

From Textbooks • Nov. 29, 2017

The decay factor simply measures how rapidly the probability of an event declines as the random variable X increases.

From Textbooks • Nov. 29, 2017

First, the underlying distribution has a binary random variable and therefore is a binomial distribution.

From Textbooks • Nov. 29, 2017

There are, for example, 36 possible outcomes from throwing just two six-sided dice where the random variable is the sum of the number of spots on the up- facing sides.

From Textbooks • Nov. 29, 2017

The myriad factors affecting innovativeness make the historian’s task paradoxically easier, by converting societal variation in innovativeness into essentially a random variable.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023