### Transform > Probability Distributions > LogNormal

Calculates the probability densities, cumulative probabilities, and inverse cumulative probabilities for a LogNormal distribution.

The lognormal distribution is the distribution of a random variable whose logarithm is normally distributed. If Y is a random variable with a normal distribution, then the random variable X = exp(Y) has a lognormal distribution. Likewise if the random variable X has a lognormal distribution then the random variable Y = log(X) is normally distributed.

NOTE: When specifying the parameters that describe an instance of LognormalDistribution we do so by specifying the mean and standard deviation of its logarithm which, by definition, is normally distributed.

### Dialog box items

•Source Column:

Enter the column you want to evaluate.

•Target Column:

Enter a storage column for the generated values. Leave blank to have VisualStat automatically name the target column.

•Statistics:

Choose from the following options:

oProbability density: Choose to calculate the probability densities.

oCumulative probability: Choose to compute the cumulative probabilities.

oInverse cumulative probability: Choose to compute the inverse of the cumulative probabilities.

•Distribution: Select the distribution for the variable.

•Mean: Enter the mean value you want to use as the center point for the lognormal distribution.

•Standard deviation: Enter the standard deviation you want to define the lognormal distribution.

### Example

Example of using the probability density function (pdf)

Probability Distributions

Web Resource: Weisstein, Eric W., Wolfram MathWorld. | Wikipedia