In Excel 2010, the Fdist function has been replaced by the F.Dist.Rt function, which has improved accuracy.
The Excel FDIST function calculates the (right-tailed) F Probability Distribution, which measures the degree of diversity between two data sets.
The syntax of the function is:
Where the function arguments are:
|x||-||The (positive) numeric value at which the function is to be evaluated.|
|deg_freedom1||-||An integer specifying the numerator degrees of freedom.|
|deg_freedom2||-||An integer specifying the denominator degrees of freedom.|
If either deg_freedom1 or deg_freedom2 are decimal numbers, these are truncated to integers by Excel.
The above chart on the right shows the right-tailed F Probability Distribution with the numerator degrees of freedom equal to 1 and the denominator degrees of freedom equal to 2.
If you want to use Excel to calculate the value of this function at x = 5, this can be done using the Fdist function, as follows:
This gives the result 0.154845745.
Further details and examples of the Excel Fdist function are provided on the Microsoft Office website.
If you get an error from the Excel Fdist function this is likely to be one of the following:
|#VALUE!||-||Occurs if any of the supplied arguments are non-numeric.|