Mean

In statistics, mean has two related meanings:

Weighted mean

The weighted mean is used, if one wants to combine average values from samples of the same population with different sample sizes:

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: ar{x} = rac{sum_{i=1}^n{w_i cdot x_i}}{sum_{i=1}^n {w_i}}

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The weights w_i represent the bounds of the partial sample. In other applications they represent a measure for the reliability of the influence upon the mean by respective values.

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