Returns the probability associated with an Ftest for equality of variances. Determines whether two samples are likely to have come from populations with the same variance.
Sample Usage
FTEST(A1:A5, B1:B5)
FTEST(A1:D3, A5:D7)
Syntax
FTEST(range1, range2)

range1
 The first sample of data or group of cells to consider for the Ftest. 
range2
 The second sample of data or group of cells to consider for the Ftest.
Notes

Any nonnumeric cells in either range are ignored in the calculation.

You can use
FTEST
orF.TEST
to perform this function.
See Also
CHITEST
: Returns the probability associated with a Pearson’s chisquared test on the two ranges of data. Determines the likelihood that the observed categorical data is drawn from an expected distribution.
FDIST
: Calculates the righttailed F probability distribution (degree of diversity) for two data sets with given input x. Alternately called FisherSnedecor distribution or Snedecor's F distribution.
FINV
: Calculates the inverse of the righttailed F probability distribution. Also called the FisherSnedecor distribution or Snedecor’s F distribution.
TTEST
: Returns the probability associated with ttest. Determines whether two samples are likely to have come from the same two underlying populations that have the same mean.
Example
Suppose you want to determine whether exam scores from this semester have a different variability than last semester. Pass the scores from each semester as arguments to FTEST
. Because the pvalue is high, we can conclude that there is not a significant difference in variability in exam scores.
A  B  

1  Scores this semester  Scores last semester 
2  92  84 
3  75  89 
4  97  87 
5  85  95 
6  87  82 
7  82  71 
8  79  
9  Solution  Formula 
10  0.8600520777  =FTEST(A2:A8, B2:B7) 