# 8.1: Appendix

- Page ID
- 8757

error\(=\sum_{i=1}^{n}\left(x_{i}-\bar{X}\right)=0\)

\[

\begin{array}{c}

{\sum_{i=1}^{n} x_{i}-\sum_{i=1}^{n} \bar{X}=0} \\

{\sum_{i=1}^{n} x_{i}=\sum_{i=1}^{n} \bar{X}} \\

{\sum_{i=1}^{n} x_{i}=n \bar{X}} \\

{\sum_{i=1}^{n} x_{i}=\sum_{i=1}^{n} x_{i}}

\end{array}

\nonumber\]