Bioequivalence and Bioavailability Forum

Dear GM.

First of all, I figured out your link to the reference:
https://www.fda.gov/downloads/drugs/guidances/ucm070930.pdf

Example from page 23 (PDF page 26 of 40).

Lower limit is the 8^th value of sorted values and upper limit is 29^th value as mentioned in the text (PDF page 27 of 40).

8 is 5^th quantile calculated from the equation as you already mentioned:
w(0.05) = mn/2 - z_crit*sqrt(mn*(m+n+1)/12) ... approximation for m+n large enough.

And 29 is 95^th quantile + 1. Here you probably forgot "+ 1" to get the right position of upper limit.
In this case there is even count of ordered data.
Lower limit is 8^th from the start, upper limit is 8^th from the end, i.e. 29^th from the start.

So you get the positions of ordered data and then you have lower and upper limit directly, you know.

Best regards,
zizou