Logistic Distribution

The Logistic distribution has density function:

f(x) = (1/b)*e-(x-a)/b * [1+e-(x-a)/b]-2

-∞<x<∞, 0<b

where

is the mean of the distribution

b

is the scale parameter

e

is the base of the natural logarithm, sometimes called Euler's e (2.71...)

    

The graphic above shows the shape of the Logistic distribution when the location parameter equals 0 and the scale parameter equals 1, 2, and 3. For a complete listing of all distribution functions, see Distributions and Their Functions.