I am looking for some help creating a formula to analyze some health data that I am looking at. I have a range of testing dates for a preventative screening and I am looking to calculate the average of the 2 highest values separated by 21 days. I will attach a sample spreadsheet of an example of what it looks like, but I want to be able to replicate this over multiple samples (around 200 or so different groupings of testings). I have played around using a few different functions, but have failed to put it all together. I appreciate help in any way possible. Thank you!
|Days Post||Test score|