Correlation Song The letter used to denote the sample (Pearson) correlation coefficient is: . Correlation describes the degree of clustering around a line the y-axis a parabola the mean . For a given scatterplot the correlation coefficient and the slope of the regression line would always sometimes never share the same sign. Hint Try playing with the applet at http://illuminations.nctm.org/Activity.aspx?id=4186 with the “show line of best fit” box checked and watch how r and the slope behave (the slope is the number that x is multiplied by). Continue