XL2000: GAMMADIST() Worksheet Function Returns #NUM! Error

In Microsoft Excel, when you use the GAMMADIST() worksheet function in a formula, a valid formula may return the Excel error #NUM!.

This issue can occur if Excel cannot calculate the distribution in 100 iterations or less.

The gamma distribution worksheet function syntax is GAMMADIST(x,alpha,beta,cumulative). Excel may not be able to calculate the distribution in 100 iterations or less if all of the following conditions are true:

• X is less than or equal to .11.
• Alpha is less than or equal to x.
• Beta is equal to 1.
• Cumulative is true.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

For more information about the GAMMADIST() worksheet function, click Microsoft Excel Help on the Help menu, type gammadist in the Office Assistant or the Answer Wizard, and then click Search to view the topic.