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2.1.8 The Poisson Distribution

The Poisson distribution is a model for the relative frequency of rare events. It is often used to determine the probability that $ X$ number of events will happen in a specific time, area or volume. The model applies to cases where each event occurs with the same probability at any part in time or location in space.

Examples

Definition 12   The Poisson distribution function with parameter $ \lambda$ (that represents the average number of events in a unit of time, area or volume) is:

$\displaystyle P_X(k) = \frac{\mathrm{e}^{-\lambda}\lambda^k}{k!} $

Remarks:


next up previous contents
Next: 2.2 Limit Laws of Up: 2.1 Probabilities and Random Previous: 2.1.7 The Binomial distribution
Eran Borenstein
2007-05-04