Physics307L:Schedule/Week 9 agenda/Weighted

Wikipedia article

 * $$\bar{x} = \frac{ \sum_{i=1}^n w_i x_i}{\sum_{i=1}^n w_i},

$$

which means:



\bar{x} = \frac{w_1 x_1 + w_2 x_2 + \cdots + w_n x_n}{w_1 + w_2 + \cdots + w_n}. $$



w_i = \frac{1}{\sigma_i^2}. $$

Excel examples

 * http://openwetware.org/wiki/Image:Weighted_mean_and_random.xlsx