Explore the least-squares best-fit (regression) line.

[list=1][br][*] Try to fit the data best you can with the red line. The SSE (Sum of the Squared Errors) for your line appears on the right next to the target SSE (the absolute minimum).[br][*] When you have done the best you can, click the checkbox to see the regression line.[br][*] Click the checkbox to hide the regression line again. Then move the points around to tweak the data set or click the Randomize Data button to get an altogether new data set, and try again![br][/list]