Median

The median is the simplest summary of a distribution's centre, with the same number of values above and below it.

Mean

Another number that summarises a distribution's centre is its mean. This is found by adding all the values, then dividing by the number of values, n.

Its value is easiest to understand as a "point of balance", as explained in the following examples.


Software support time

Sunshine hours

For a skew distribution such as this, the mean is further into the long tail than you might have expected!