Poisson

A discrete random variable is said to have a Poisson distribution, with parameter if it has a probability mass function given by:

Properties

Examples

The Poisson distribution may be useful to model events such as:

  • The number of meteorites greater than 1-meter diameter that strike Earth in a year;
  • The number of laser photons hitting a detector in a particular time interval;
  • The number of students achieving a low and high mark in an exam; and
  • Locations of defects and dislocations in materials.
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