Normal distribution
This page provides the definition for a mathematics term.
About this resource
A glossary of terms used in mathematics.
Normal distribution
A family of theoretical distributions that is useful as a model for some continuous random variables.
Each member of this family of distributions is uniquely identified by specifying the mean µ and standard deviation σ (or variance σ2). As such, µ and σ (or σ2), are the parameters of the normal distribution, and the distribution is sometimes written as Normal(µ, σ) or Normal(µ, σ2).
The probability density function of a normal distribution is a symmetrical, bell-shaped curve, centred at its mean µ. The graphs of the probability density functions of two normal distributions are shown below, one with µ = 50 and σ = 15 and the other with µ = 50 and σ = 10.
Curriculum achievement objectives references
Probability: Levels 7, 8.
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