r, or the regression coefficient, is a simple value that is used when finding the closeness of a regression equation to the actual data points which it is trying to show a correlation between. r will range from −1 to 1. The closer the value for a regression equation/model is to 0, the worse the model will be for showing a trend in the data. So a value closer to −1 or 1 for r would therefore correspond to a more reliable and accurate equation/model to represent the data.
If you have a graphing calculator, such as a TI-84, then your math teacher should be able to help you to find an r value for a regression (or you can just look it up on www.youtube.com).
Just a note for the future: When you are trying to find r, a value may appear noted as r2. This is basically the same concept as r, and they both show the closeness of a regression model/equation to the data which it tries to represent. The only difference is that r2 is r times r, or in standard English, the value of the regression coefficient squared.
I hope that helps!
