>So if, in Excel, you can fit a regression from "scratch", (i.e. not using any built-in regression functions) and use the built-in functions for convenience, th

>So if, in Excel, you can fit a regression from "scratch", (i.e. not using any built-in regression functions) and use the built-in functions for convenience, that's fine. I suppose it depends on what you mean by "can". Much like whiteboard interviewing, I bet I can't sit down today and implement a regression from scratch, because I'm out of practice. I have had no need to retain that information; there are tools that do it for me. Could I do it quickly with a stats 101 textbook in my lap (or 10 minutes of Googling)? Absolutely.