The normal distribution has the following properties:

It has two parameters, the mean *a* and the width , which can be estimated from a sample by the following estimators:

In the statistical literature the probability density function of the normal distribution is often denoted by ).
The *standard normal distribution*
has zero mean and unit variance, i.e.

The corresponding distribution function is denoted by

This is the complement of what is usually denoted as *error function*
(the name is also used in other contexts), i.e. .

Rudolf K. Bock, 7 April 1998