Lognormal Distribution

If a random variable has a Lognormal Distribution, then its natural logarithm has a Normal Distribution. This is the meaning of the term Lognormal.

Like the Exponential Distribution, the Lognormal Distribution can only be used for variables which are always positive.

A Lognormal Distribution can be useful for modelling variables such as Cohesion, for example, which may have a large peak in the distribution near zero and then taper off gradually for larger values.