How I set up a 4 parameter logistic curve in excel
If you're trying to fit a 4 parameter logistic curve in excel, you've probably realized that the standard trendline options just don't cut it. While Excel is great for linear regressions or simple polynomials, it doesn't give you a "4PL" button out of the box. I've spent a lot of time wrestling with bioassays and concentration-response data, and honestly, once you get the hang of the manual setup, it's actually more flexible than using some expensive specialized software. ...