LOGNORMDIST function
Returns the cumulative lognormal distribution of x, where ln(x) is normally distributed with parameters mean and standard_dev. Use this function to analyze data that has been logarithmically transformed.
Syntax
LOGNORMDIST(x,mean,standard_dev)
X is the value at which to evaluate the function.
Mean is the mean of ln(x).
Standard_dev is the standard deviation of ln(x).
Remarks

If any argument is nonnumeric, LOGNORMDIST returns the #VALUE! error value.

If x ≤ 0 or if standard_dev ≤ 0, LOGNORMDIST returns the #NUM! error value.

The equation for the lognormal cumulative distribution function is:
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example

Create a blank workbook or worksheet.

Select the example in the Help topic.
Note Do not select the row or column headers.
Selecting an example from Help

Press CTRL+C.

In the worksheet, select cell A1, and press CTRL+V.

To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.

