Section: STEM · MathematicsDifficulty: Medium

Normal Distribution

USUK

A symmetric bell-shaped probability distribution defined by mean and standard deviation.

Also: Gaussian distribution · bell curve

Definition

The normal distribution (also called the Gaussian distribution) is a continuous probability distribution that produces a symmetric bell-shaped curve, fully characterized by its mean and standard deviation. It is central to statistics because many natural phenomena approximately follow it, and the Central Limit Theorem states that the average of many independent random variables tends toward a normal distribution. About 68% of values fall within one standard deviation of the mean.

Example

Heights of adult humans follow an approximately normal distribution; if the mean height is 170 cm with a standard deviation of 10 cm, about 95% of people will have heights between 150 cm and 190 cm.

Synonyms

  • Gaussian distribution
  • bell curve
  • normal curve

Antonyms / Opposites

  • uniform distribution
  • skewed distribution

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  • Probability
  • Statistics
  • Standard Deviation
  • Central Limit Theorem

Dictionary Entry

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