FINV

FINV(probability, degrees_freedom1, degrees_freedom2)

Returns the inverse of the probability distribution function for an f distribution (left tailed).

probability	The probability associated with this distribution.
degrees_freedom1	The numerator degrees of freedom.
degrees_freedom2	The denominator degrees of freedom.

REMARKS

* This function is only available for backwards compatibility and should not be used.
* F.INV.RT was added in Excel 2010 to replace this function.
* The f distribution is a continuous distribution
* The random variable returned by this function is often referred to as a critical value.
* If "probability" < 0, then #NUM! is returned.
* If "probability" > 1, then #NUM! is returned.
* If "probability" is not numeric, then #VALUE! is returned.
* If "degrees_freedom1" < 1, then #NUM! is returned.
* If "degrees_freedom1" = 10^10, then #NUM! is returned.
* If "degrees_freedom1" is not an integer, it is truncated.
* If "degrees_freedom1" is not numeric, then #VALUE! is returned.
* If "degrees_freedom2" < 1, then #NUM! is returned.
* If "degrees_freedom2" = 10^10, then #NUM! is returned.
* If "degrees_freedom2" is not an integer, it is truncated.
* If "degrees_freedom2" is not numeric, then #VALUE! is returned.
* If this function does not converge after 100 iterations, then #N/A is returned.
* For the Microsoft documentation refer to support.microsoft.com

	A
1	=FINV(0.01, 6, 4) = 15.207
2	=FINV(0.5, 1, 2) = 0.667
3	=FINV(0.5, 1, 1) = 1
4	=FINV(FDIST(15.207, 6, 4), 6, 4) = 15.207
5	=FINV(0.5, 1, -2) = #NUM!
6	=FINV(0.5, -1, 2) = #NUM!
7	=FINV(0.5, "some text", 2) = #VALUE!