Declaration: 
PerformFTest (Data1, Data2: TDoubleArray; OneSided: boolean; var Mean1, Mean2, Stdv1, Stdv2, FStatistic: double; var df1, df2: integer): double; 
The function PerformFTest returns the probability associated with an F test (probability which indicates the likelihood that two samples have come from the same two underlying populations having the variance).
The parameters Data1 and Data2 contain the data. The parameter OneSided has to be TRUE for onesided tests, or FALSE for twosided tests. The function returns additional parameters obtained during the F test calculation:
Mean1, Mean2 
means of the two samples 
Stdv1, Stdv2 
standard deviations of the two samples 
FStatistic 
F statistic 
df1, df2 
degrees of freedom 

