並前往https://medium.com/qiubingcheng/%E7%B0%A1%E5%96%AE%E7%B7%9A%E6%80%A7%E5%9B%9E%E6%AD%B8-simple-linear-regression-%E7%9A%84%E5%85%AC%E5%BC%8F%E6%8E%A8%E5%B0%8E-formula-derivation-5ae26090e8de