Hi, guys. I think it should be in advanced statistics since I did it at university, if no, I am sorry.
A few years ago I made an experiment using RSM, 2 independent variables and 1 dependent, in general 9 levels and 5 repetition each
I have got a quadratic regression in MathCad and now I need to make an analysis. But since I forgot everything I definitelly will never be able to do it in MathCad and I am looking for the simplest way.

Where and how can I calculate R2, correlation coefficient for my model and coefficient of variables? I found some tools online but they all are for linear regression and one variable.

Thank you