Linear Regression,
a geogebra
animation
There are 5 points graphed below, together with the regression line that is the best linear fit to the 5 points. The coordinates of point E can be changed. To change the xcoordinate, click and drag the point on the green horizontal bar. To change the ycoordinate, click and drag the point on the green vertical bar. Note that the
regression line and the values for
R and R^{2} change. R is the correlation coefficient, and R^{2} is the coefficient of determination.
As the point E moves further from the regression line, what happens to
R and R^{2}?
For which coordinates of E would you have the most confidence in the regression line as a predictor? 
G. Battaly, WCC, Created with GeoGebra 
Â©G. Battaly, 2010 
