The arithmetic mean is what is commonly called the average of the numbers. The value of is always between the least and the greatest of the numbers (http://planetmath.org/MinimalAndMaximalNumber) . If the numbers are all positive, then for all .
A generalization of this concept is that of weighted mean, also known as weighted average. Let be numbers whose sum is not zero, which will be known as weights. (Typically, these will be strictly positive numbers, so their sum will automatically differ from zero.) Then the weighted mean of is defined to be
In the special case where all the weights are equal to each other, the weighted mean equals the arithmetic mean.
|Date of creation||2013-03-22 11:50:42|
|Last modified on||2013-03-22 11:50:42|
|Last modified by||drini (3)|