FDIST function
Returns the F probability distribution. 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.
Syntax
FDIST(x,degrees_freedom1,degrees_freedom2)
X is the value at which to evaluate the function.
Degrees_freedom1 is the numerator degrees of freedom.
Degrees_freedom2 is 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 degrees_freedom1 or degrees_freedom2 is not an integer, it is truncated.

If degrees_freedom1 < 1 or degrees_freedom1 ≥ 10^10, FDIST returns the #NUM! error value.

If degrees_freedom2 < 1 or degrees_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 degrees_freedom1 and degrees_freedom2 degrees of freedom.
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.

