简单相关系数的基本原理是把每一对观测值(x<sub>i</sub>，y<sub>i</sub>)中的x<sub>i</sub>值与均值<img width="20" height="44" src="http://www.weimei168.com/uploads/202208/20211124153211_2418.gif" />的距离与相应的y<sub>i</sub>值与均值<img width="22" height="48" src="http://www.weimei168.com/uploads/202208/20211124153212_7194.gif" />的距离( )