The upper r squaredr2 that measures the proportion of total
variation in the response variable that is explained by the least squares
regression line is called the Coefficient of
Determination (R - squared).
To add, it is a number between 0 and 1, inclusive.
If R2 = 0, the least-squares regression line has no explanatory value.
If R2 = 1, the least-squares regression line explains 100% of the
variation in the response variable.
Measures how well the LS-regression line describes the
relation between the explanatory and response variables.
As the explanatory ability of the line decreases, the
coefficient of determination, R2, also decreases.
