Distribution Analyses

Parametric Distributions

A parametric family of distributions is a collection of distributions with a known form that is indexed by a set of quantities called parameters. Methods based on parametric distributions of normal, lognormal, exponential, and Weibull are available in a distribution analysis. This section describes the details of each of these distributions. Use of these distributions is described in the sections "Graphs" and "Curves" later in this chapter.

You can use both the density function and the cumulative distribution function to identify the distribution. The density function is often more easily interpreted than the cumulative distribution function.

Parametric Distributions

Normal Distribution

Lognormal Distribution

Exponential Distribution

Weibull Distribution