**Examples**

- The number of Microorganisms within a microscope field.
- The number of Neuron spikes within a 10ms period.
- Suspension of blood cells in a counting chamber: Number of cells per square of the counting chamber.

**Remarks:**

- Often, instead of the expected number , the proportion of successful events per time area or volume unit is known. In this case can be determined by where is the number of units we consider. For example: if we know that out of people are females then if we construct a Poisson r.v. that counts the number of females within a sample of then we will use .
- When is small and is large, the Binomial distribution can be approximated with a Binomial distribution.

2007-05-04