Random variable
This page provides the definition for a mathematics term.
About this resource
A glossary of terms used in mathematics.
Random variable
A property that can have different values because there is an element of chance involved in obtaining any value for the property.
A random variable is often represented by an upper case letter, say X.
Example 1
The random selection of an individual from a population is subject to chance. The height of a selected individual will depend on the individual selected and is therefore a random variable. This may be written as, let X represent the height of a randomly selected individual.
Example 2
The random selection of 10 individuals from a population is subject to chance. The number of left-handed people in a sample of 10 individuals will depend on the individuals selected and is therefore a random variable. This may be written as, let X represent the number of left-handed people in a random selection of 10 individuals.
Curriculum achievement objectives references
Probability: Levels 7, 8.
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