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What is the normal distribution?

MathematicsLesson on requestFree to read

Quick answer

The normal distribution is a symmetric, bell-shaped curve that describes how many natural measurements cluster around an average. Most values fall near the middle, with fewer at the extremes — think heights, test scores, or measurement errors. It's the classic symmetric 'bell curve'.

Key things to understand

  1. It's the classic symmetric 'bell curve'.
  2. Most values cluster near the average (the middle of the curve).
  3. It's defined by its mean (center) and standard deviation (spread).
  4. About 68% of values fall within one standard deviation of the mean.

People also ask

What is a normal distribution?
A bell-shaped curve where data clusters symmetrically around the average, with fewer values at the extremes.
Why is the normal distribution important?
Many natural and statistical quantities follow it, making it central to probability and statistics.
What is the 68-95-99.7 rule?
About 68%, 95%, and 99.7% of values lie within one, two, and three standard deviations of the mean.