regression

phet.colorado.edu

Create your own scatter plot or use real-world data and try to fit a line to it! Explore how individual data points affect the correlation coefficient and best-fit line.

phet.colorado.edu

Drag data points and their error bars and watch the best-fit polynomial curve update instantly. You choose the type of fit: linear, quadratic, or cubic. The reduced chi-square statistic shows you when the fit is good. Or you can try to find the best fit by manually adjusting fit parameters.