The correlation coefficient
, typically denoted r
measures how strongly two numerical variables are linked to each other. The following is the formula for r
, with a brief description of the variables:
- The number of data points is given by n.
- The capital sigma denotes addition of several terms.
- The data points are represented by xi and yi.
- The mean of the xi is denoted by x with a horizonatal bar over it.
- The standard deviation of the xi is denoted by sx.
- The mean of the yi is denoted by y with a horizonatal bar over it.
- The standard deviation of the yi is denoted by sy.