In Excel 2010, the Ftest function has been renamed F.Test.
Although the Ftest function has been replaced, Excel 2010 has kept this function, (stored within the list of compatibility functions), for compatibility with earlier versions of Excel.
The Excel FTEST function returns the FTest for two supplied arrays. I.e. the function returns the twotailed probability that the variances in in the two supplied arrays are not significantly different.
The syntax of the Excel Ftest function is:
where the supplied array1 and array2 are two arrays of data values, that represent samples from two different populations. If the arrays contain logical values or empty cells, these are ignored by the Ftest function.
Columns A and B of the above spreadsheet on the right contain the reaction times of a sample of individuals from two different groups. Cell C2 of the spreadsheet shows the Excel FTEST function used to show the probability that there is no significant difference between the variances of the two data sets.
The result of the Ftest function in cell C2 is 0.954035559.
Further examples of the Excel Ftest function can be found on the Microsoft Office website.
If you get an error returned from the Excel Ftest Function, this is likely to be the Excel #DIV/0! error :
#DIV/0!    Occurs if either:
