Susan Dean and Barbara Illowsky's Collaborative Statistics: "Chapter 12: Linear Regression and Correlation, Section 6: The Correlation Coefficient"

Read this section, which describes the formula for computing the correlation coefficient. It may be useful to save this resource for future reference to this formula. Note that the formula uses the Greek letter sigma, \( \Sigma \), as the summation symbol. For instance, \( \sum x_i=x_1+x_2+x_3 \) when \( i=1,2,3 \).