elements you’re averaging. Here’s what the Average Pie looks like using the simple average example we
just gave you.
Here’s how the Average Pie works mathematically. The horizontal line in the middle means divide. If you
know the total and the number of things, just divide to get the average (18 ÷ 3 = 6). If you know the total
and the average, just divide to get the number of things (18 ÷ 6 = 3). If you know the average and the
number of things, simply multiply to get the total (6 ÷ 3 = 18). The key to most average questions is
finding the total.
Here’s another simple example:
Problem: If the average of three test scores is 70, what is the total of all three test scores?
Solution: Just put the number of things (3 tests) and the average (70) in the pie. Then multiply to find the
total, which is 210.
Total
When calculating
averages and means,
always find the total.
It’s the one piece of
information that
ETS loves to withhold.Averages: Advanced Principles
To solve most difficult average problems, all you have to do is fill out one or more Average Pies. Most of
the time you will use them to find the total of the number being averaged. Here’s an example: