When variables are standardized, their means are equal to 0 and standard deviations are equal to 1, the regression equation is simpler: b = r and A = 0. As a result, the regression line looks like this:
ZY’ = (r)(ZX)
ZY’ represents the expected standard score for Y, r represents the correlation, and ZX represents the standardized score for X. For standardized variables, the slope of the regression equation is r.
