# How do I use the empirical rule?

##### 1 Answer

Mar 5, 2015

It can give you quick answers without looking up in tables.

Ususally, you standardise the normal distribution, and then look up its z-value in a table.

If you memorise just a few numbers, you can work quicker.

The numbers are

The remaining two times

Below is a graph (from Wikipedia) that summarizes: