FDIST function
Returns the (righttailed) F probability distribution (degree of diversity) for two data sets. You can use this function to determine whether two data sets have different degrees of diversity. For example, you can examine the test scores of men and women entering high school and determine if the variability in the females is different from that found in the males.
Important This function has been replaced with one or more new functions that may provide improved accuracy and whose names better reflect their usage. This function is still available for compatibility with earlier versions of Excel. However, if backward compatibility is not required, you should consider using the new functions from now on, because they more accurately describe their functionality.
For more information about the new functions, see F.DIST function and F.DIST.RT function.
Syntax
FDIST(x,deg_freedom1,deg_freedom2)
The FDIST function syntax has the following arguments:

X Required. The value at which to evaluate the function.

Deg_freedom1 Required. The numerator degrees of freedom.

Deg_freedom2 Required. The denominator degrees of freedom.
Remarks

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

If x is negative, FDIST returns the #NUM! error value.

If deg_freedom1 or deg_freedom2 is not an integer, it is truncated.

If deg_freedom1 < 1 or deg_freedom1 ≥ 10^10, FDIST returns the #NUM! error value.

If deg_freedom2 < 1 or deg_freedom2 ≥ 10^10, FDIST returns the #NUM! error value.

FDIST is calculated as FDIST=P( F>x ), where F is a random variable that has an F distribution with deg_freedom1 and deg_freedom2 degrees of freedom.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How do I copy an example?

Select the example in this article.
Important Do not select the row or column headers.
Selecting an example from Help

Press CTRL+C.

In Excel, create a blank workbook or worksheet.

In the worksheet, select cell A1, and press CTRL+V.
Important For the example to work properly, you must paste it into cell A1 of the worksheet.

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.
After you copy the example to a blank worksheet, you can adapt it to suit your needs.

