Weighted mean

From Wikinfo

Given a set of data, X={x₁, x₂, ..., x_n} and corresponding weights, W={w₁, w₂, ..., w_n} the weighted mean is calculated as

<math>

\bar{x} = \frac{ \sum_{i=1}^n w_i \cdot x_i}{\sum_{i=1}^n w_i} </math>

Note that if all the weights are equal, the weighted mean is the same as the arithmetic mean.

back to summary statistics -- central tendency

See also: average

References

• Adapted from the Wikipedia article, "Weighted_mean" http://en.wikipedia.org/wiki/Weighted_mean, used under the GNU Free Documentation License