I have a TI calculator as well, but I did a google search and found these hits about linear regression using a Casio. You'll have to look for your calculator model.
Does anyone know how to do these? I need the help because I bought a casio graphing calc and the professor taught the class in Texas Instrument terms. I can't figure out how to do it since I couldn't follow along in class and I can't afford to buy another calculator. If I post here would anyone be able to help me? Thanks!