Regression Line - Cost of Homes compared to Size
Classroom Example, Prof. Battaly                                                                                           Statistics     video of this demo

This is a graph of data for the the number of square feet (as 100 sq ft) as the independent variable and cost
in thousands of dollars for the dependent variable.

Use the PLAY button on the lower right to see the points plotted and the Regression Line drawn.
Then note the correlation coefficient, r, and the coefficient of determination, r², which is computed from the data points.

The last point added to the demo is the predictor point P. Click and drag P to see the cost in $ thousands predicted by the regression equation.

What cost does the regression equation predict for a home of 3100 square feet?

If you explore by changing the values of the data points, be sure to keep  20 < x < 45 and   400 < y < 850.  Have fun!

Gertrude Battaly, Statistics Class, Created with GeoGebra                                                                                 Statistics