In mathematics and statistics, the arithmetic mean (pronunciation: /ˌærɪθˈmɛtɪk ˈmiːn/, stress on third syllable of "arithmetic"), or simply the mean or average when the context is clear, is the sum of a collection of numbers divided by the number of numbers in the collection. The collection is often a set of results of an experiment, or a set of results from a survey. The term "arithmetic mean" is preferred in some contexts in mathematics and statistics because it helps distinguish it from other means, such as the geometric mean and the harmonic mean.
In addition to mathematics and statistics, the arithmetic mean is used frequently in fields such as economics, sociology, and history, and it is used in almost every academic field to some extent. For example, per capita income is the arithmetic average income of a nation's population.
While the arithmetic mean is often used to report central tendencies, it is not a robust statistic, meaning that it is greatly influenced by outliers (values that are very much larger or smaller than most of the values). Notably, for skewed distributions, such as the distribution of income for which a few people's incomes are substantially greater than most people's, the arithmetic mean may not accord with one's notion of "middle", and robust statistics, such as the median, may be a better description of central tendency.
(Stevie Wonder)
Over time, I've been building my castle of love
Just for two, -
Though you never knew you were my reason
I've gone much too far for you now to say
That I've got to throw my castle away
Over dreams, -
I have picked out a perfect come true
Though you never knew it was of you -
I've been dreaming
The sandman has come from too far away
For you to say come back some other day
And though you don't believe that they do
They do come true
For did my dreams
Come true when I looked at you
And maybe too, if you would believe
You too might be
Overjoyed, over loved, over me
Over hearts, I have painfully turned every stone
Ooh, just to find, -
I had found what I've searched to discover
I've come much too far for me now to find
The love that I sought can never be mine
And though you don't believe that they do
They do come true
For did my dreams
Come true when I looked at you
And maybe too, if you would believe
You too might be
Overjoyed, over loved, over me
And though the odds say improbable
What do they know
For in romance
All true love needs is a chance
and maybe with a chance you may find
You too like I
Overjoyed, over loved, over you