Determine the p-value in a test comparing two variances

I am looking for an Excel function or a formula that will give me the p-value for an F-test comparing the variances of two populations. I can get the p-value using the "F-Test Two-Sample for Variances" tool in the Data Analysis Tool Pak, but I cannot find the p-value formula behind the tool. I use the CHISQ.DIST.RT function for single-variance problems, but I do not see how I can use it when comparing two variances, with two different degrees of freedom. Any ideas would be greatly appreciated. Thanks.

Originally Posted by Jim_Robison

I can get the p-value using the "F-Test Two-Sample for Variances" tool in the Data Analysis Tool Pak, but I cannot find the p-value formula behind the tool

I thought it is indeed part of the Data Analysis output -- if you're satisfied with that instead of a formula.

In either case, please provide an example Excel file (see the bright yellow banner at the top of the webpage) with data, formulas and some description of your use of the Data Analysis tool.

For the latter, that might be a screenshot or field-by-field details.

Some other thoughts....

1. Do a google search for "excel p-value for f-test of two variances" without quotes. Off-hand, I found https://statisticsbyjim.com/hypothes...ces-test-excel . Haven't even looked at it yet.

2. Wander around http://www.real-statistics.com . Usually a good source of such things. Caveat: He does make mistakes, though.

Please see the attached spreadsheet. The application I am building will not work with the Data Analysis tool. I am looking for an Excel function(s) or formula that will produce the p-value.

Thanks MrShorty, that did it. I ended up using F.DIST.RT but FDIST was the key.