This document discusses Spearman's rank correlation coefficient. It provides formulas and explanations for calculating the coefficient when: 1) Actual ranks are given 2) Ranks are not given and need to be assigned 3) There are equal or tied ranks The coefficient measures the strength and direction of association between two ranked variables. It ranges from -1 to 1, where 1 is total agreement in ranking, -1 is total disagreement, and 0 is no correlation. The document also lists properties of Spearman's rank correlation.