| (1) | r =r_{xy} = = \frac{ \sum\limits^n_{i=1} (x_i - \bar x)( y_i - \bar y)}{\sqrt{\sum\limits_i (x_i - \bar x)} \cdot \sqrt{\sum\limits_i (y_i - \bar y)}} |
where
y =\hat x | estimator of variable x |
See also
Formal science / Mathematics / Statistics / Regression / Linear Regression