<p>Can someone please explain the concept of 'Regressions' in the Statistics and Data Analysis portion of the SAT Math Level 2 Subject tests? Barrons doesn't explain it pretty well and neither does Khan Academy have any topic related to the regressions (except the regression line in statistics plots). I'm not able to understand the general equations and structures of linear regression, quadratic regression and exponential regression. Also, how do I choose between using one of them for solving a question?</p>

<p>I would also be grateful if someone could explain me how to solve a regression question using a TI-89? I can't seem to find the correct steps to solve a question using the TI-89.</p>

<p>Thanks!</p>

<p>PS. Couldn't find anything on spark notes either.</p>