When do we need to fit a lognormal distribution to our skewed histograms? This article considers the basic properties of the lognormal family of distributions and reveals some interesting and time-saving characteristics that are useful when analyzing data.

The lognormal family of distributions

While software facilitates the use of lognormal distributions, the following formulas are given here in the interest of clarity of notation. If X is a lognormally distributed random variable with parameters alpha and beta, then Y = ln(X) will be a normally distributed variable with:

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