Statistics for Maintenance Modelling: Continuous Lifetime Distributions 2

# The Probability Density Function for the Logistic Distribution¤

The logistic function could be used as a cumulative distribution function but it is preferable to add the parameters and to allow flexibility in the shape in a similar way to the how they are used to give the standard normal distribution greater flexibility. As a result, the probability density function of the logistic distribution is:

f(t) = for > 0. The mean is and the variance is .

The effects of changing and can be seen in these graphs of f(t), but you can click on them for an interactive version in Excel where you can experiment with different values yourself.