Average

In mathematics, an average is a measure of the "middle" or "typical" value of a data set. It is thus a measure of central tendency.

In the most common case, the data set is a list of numbers. The average of a list of numbers is a single number intended to typify the numbers in the list. If all the numbers in the list are the same, then this number should be used. If the numbers are not the same, the average is calculated by combining the numbers from the list in a specific way and computing a single number as being the average of the list.

Many different descriptive statistics can be chosen as a measure of the central tendency of the data items. These include the arithmetic mean, the median, and the mode. Other statistics, such as the standard deviation and the range, are called measures of spread and describe how spread out the data is.

The most common statistic is the arithmetic mean, but depending on the nature of the data other types of central tendency may be more appropriate. For example, the median is used most often when the distribution of the values is skewed with a small number of very high or low values, as seen with house prices or incomes. It is also used when extreme values are likely to be anomalous or less reliable than the other values (e.g. as a result of measurement error), because the median takes less account of extreme values than the mean does.


Read more about Average:  Calculation, Types, Solutions To Variational Problems, Miscellaneous Types, In Data Streams, Average Values of Functions, Etymology

Famous quotes containing the word average:

    All the average human being asks is something he can call a home; a family that is fed and warm; and now and then a little happiness; once in a long while an extravagance.
    Mother Jones (1830–1930)

    The average Kentuckian may appear a bit confused in his knowledge of history, but he is firmly certain about current politics. Kentucky cannot claim first place in political importance, but it tops the list in its keen enjoyment of politics for its own sake. It takes the average Kentuckian only a matter of moments to dispose of the weather and personal helath, but he never tires of a political discussion.
    —For the State of Kentucky, U.S. public relief program (1935-1943)

    Always remember that a child doesn’t have to be average to be normal. Children with very different temperaments can be equally successful.
    Lawrence Kutner (20th century)