This is one of the more common statistics you will see. And it's
easy to compute. All you have to do is *add* up all the values
in a set of data and then *divide* that sum by the number of
values in the dataset. Here's an example:

Let's say you are writing about the World Wide Widget Co. and the salaries of its nine employees.

The CEO makes $100,000 per year,

Two managers make
$50,000 per year,

Four factory workers make $15,000 each, and

Two
trainees make $9,000 per year.

So you **add** $100,000 + $50,000 + $50,000 + $15,000 + $15,000
+ $15,000 + $15,000 + $9,000 + $9,000 (all the values in the set of
data), which gives you $278,000. Then *divide* that total by 9
(the number of values in the set of data).

That gives you the *mean*, which is $30,889.

Not a bad average salary. But be careful when using this number. After all, only three of the nine workers at WWW Co. make that much money. And the other six workers don't even make half the average salary.

So what statistic should you use when you want to give some idea
of what the average *worker* at WWW Co. is earning? It's time to
learn about the *median*.

Read the rest of Robert's statistics lessons for people who don't know math.

© Robert Niles. Read more in the column archive.