LogNormal Command

LogNormal( <Mean>, <Standard Deviation>, <Variable Value> ): Evaluates the cumulative distribution function of a log-normal distribution at variable value, i.e. calculates the probability P(X ≤ v) where X is a random variable with a log-normal distribution defined by the given parameters mean and standard deviation.
LogNormal( <Mean>, <Standard Deviation>, <Variable Value>, <Boolean Cumulative> ): If Cumulative = true, evaluates the cumulative distribution function of a log-normal distribution with given mean and standard deviation at the given variable value, otherwise it evaluates the probability density function of the distribution at variable value.
LogNormal( <Mean>, <Standard Deviation>, x, <Boolean Cumulative> ): If Cumulative = true, creates the cumulative density function (cdf) of a log-normal distribution with given mean and standard deviation, otherwise it creates the probability density function (pdf) of the distribution.

This syntax returns the probability at a given value, that is the area under the log-normal distribution curve to the left of the given x-coordinate.