Hi everyone. I'm a graduate student and am struggling with something that may possibly be trivial. So, my research is creating a mathematical model to represent a real system. I have data points from my real system that I want to compare my model to. How do I do a regression analysis and get an r^2 value for the data points fit to my model? Excel wants to fit it to a line and then do a regression analysis. I tried to figure out how to do it by hand, but am only finding linear regression analyses... The model is something like this; y=a/(1+b*x) Where a and b are material constants. I went ahead and plugged in the data points that I have from the experimental publication into my model and I know a regression analysis says something about how close my data is to my model, for the life of me I cannot find anything useful online to help me calculate this. Can anyone help me out here?