第三段：

... , specifically calculated to emphasize the winner and de-emphasize all the losers: the resultant $x$ value will be $\sum_{i=1}^{k} w_i \cdot x_i$

代码：

, specifically calculated to emphasize the winner and de-emphasize all the losers: the resultant $x$ value will be 
$$\sum_{i=1}^{k} w_i \cdot x_i$$