FINV function
Returns the inverse of the (righttailed) F probability distribution. If p = FDIST(x,...), then FINV(p,...) = x.
The F distribution can be used in an Ftest that compares the degree of variability in two data sets. For example, you can analyze income distributions in the United States and Canada to determine whether the two countries have a similar degree of income diversity.
Important This function has been replaced with one or more new functions that may provide improved accuracy and whose names better reflect their usage. This function is still available for compatibility with earlier versions of Excel. However, if backward compatibility is not required, you should consider using the new functions from now on, because they more accurately describe their functionality.
For more information about the new functions, see F.INV function and F.INV.RT function.
Syntax
FINV(probability,deg_freedom1,deg_freedom2)
The FINV function syntax has the following arguments:

Probability Required. A probability associated with the F cumulative distribution.

Deg_freedom1 Required. The numerator degrees of freedom.

Deg_freedom2 Required. The denominator degrees of freedom.
Remarks

If any argument is nonnumeric, FINV returns the #VALUE! error value.

If probability < 0 or probability > 1, FINV returns the #NUM! error value.

If deg_freedom1 or deg_freedom2 is not an integer, it is truncated.

If deg_freedom1 < 1 or deg_freedom1 ≥ 10^10, FINV returns the #NUM! error value.

If deg_freedom2 < 1 or deg_freedom2 ≥ 10^10, FINV returns the #NUM! error value.
FINV can be used to return critical values from the F distribution. For example, the output of an ANOVA calculation often includes data for the F statistic, F probability, and F critical value at the 0.05 significance level. To return the critical value of F, use the significance level as the probability argument to FINV.
Given a value for probability, FINV seeks that value x such that FDIST(x, deg_freedom1, deg_freedom2) = probability. Thus, precision of FINV depends on precision of FDIST. FINV uses an iterative search technique. If the search has not converged after 100 iterations, the function returns the #N/A error value.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How do I copy an example?

Select the example in this article.
Important Do not select the row or column headers.
Selecting an example from Help

Press CTRL+C.

In Excel, create a blank workbook or worksheet.

In the worksheet, select cell A1, and press CTRL+V.
Important For the example to work properly, you must paste it into cell A1 of the worksheet.

To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.
After you copy the example to a blank worksheet, you can adapt it to suit your needs.

