The Poisson Distribution is a discrete distribution which takes on the values X = 0, 1, 2, 3, ... . It is often used as a model for the number of events (such as the number of telephone calls at a business or the number of accidents at an intersection) in a specific time period. It is also useful in ecological studies, e.g., to model the number of prairie dogs found in a square mile of prairie.

The Poisson distribution is determined by one parameter, lambda.

The distribution function for the Poisson Distribution is:

f(x) = exp(-1*lambda) lambda^x / x!

In our applet, R. A. is fishing at Mentone Beach and observing the number of sharks seen in an area one square mile in different one hour time periods. Use the "Fish" button to run the applet. To change the parameter lambda, type in the value and hit the "Clear" button.

Other applets related to probability and statistics.
This applet was written by Charles Stanton