Facts about Least-Squares Regression
1. Distinguishing between explanatory and response variables is essential in regression.
2. There is a close connection between correlation and the LSRL's slope.
b=r(sy/Sx)
b and r are either positive or both negative.
3. The LSRL of y on x always passes through the point (x bar, y bar)
4. Correlation, r, describes strength and direction of a linear relationship. r^2, the coefficient of determination, is the fraction of the variation in y values that is explained by the LSRL of y on x.