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Starting the Applet and setting the conditions
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This applet lets you estimate the regression line and to guess the value of Pearson's correlation. Indicate your estimate of the regression line by drawing a line on the scatterplot. When you release the mouse button, the mean square error (MSE which is the average squared deviation of points from the line) is displayed. You can draw another line and see if you can lower the MSE. To see the best fitting line (by the criterion of least squares) select the "Draw regression line" option. To see the MSE for the best fitting line, select the "Show minimum MSE" option.

Five possible values of Pearson's correlation are listed. One of them is the correlation for the data displayed in the scatterplot. Guess which one it is. To see the correct value, click on the "Show r" button.

Click the "New Data" button to try again.