/sci/ - Science & Math

I've got this spreadsheet full of data, it has 3 datapoints: s, b and r.

s and b are plugged into a script (which takes a long time to run and I don't have the source code for) and produce r, the same s and b values don't always produce the same r but they're fairly close to each other. How would I go about converting this data into a formula which estimates the value of r when given an s and b value?