Mathhelp,
I know it is too late to help, but I also got y=220.228x-111.942.
I have both a B.A. and and M.S. in Applied Mathematics and a Ph.D. in Biostatistics. This despite the fact that my only “B” in a math course between grades seven and twelve was in a probability and statistics course. Critical thinking is far more important than remembering formulas in statistics; in fact I don’t remember most of the basic statistics formulas and I am now a full Professor of Biostatistics at a major medical school! (And I have no idea why they are teaching exponential regression in high school; it is something usually taught to graduate students.)