The Weighted Mean
Weighted Mean of a variable \(X\) by multiplying each value by its corresponding weight and dividing the sum of the products by the sum of the weights.
That is for some variable \(X\) which takes the (quantitative) values \(\{x_1,...,x_n\}\) which have corresponding weights \(\{w_1,...,w_n\}\) we calculate the weighted mean by the following formula:
\[\overline{X}=\frac{\Big(\sum_{i=1}^nw_i\cdot x_i\Big)}{{\sum w}}\]