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.
![image\lognormal4.gif Lognormal distribution](https://www.rocscience.com/assets/help/swedge/images/image/figures/fig_lognormal_dist.gif)