The Median

The median is the middle number of a set of data, or the average of the two middle numbers (if there are an even number of data points).

Example 1:

Find the median of the data set

$0.3, 6.2, 1.5, 0.7, 5.1, 2.3, 3.0$ .

The first job is to put the data in order from least to greatest.

$0.3, 0.7, 1.5, 2.3, 3.0, 5.1, 6.2$

Now count: there are seven data points. So the median is the middle one, the fourth number:

$2.3$

Example 2:

Find the median of the data set

$71, 93, 50, 82, 12, 16, 55, 58$ .

Put the data in order from least to greatest.

$12, 16, 50, 55, 58, 71, 82, 93$

Now count: there are eight data points. The middle two are $55$ and $58$ , the fourth and fifth numbers.

So, the median is the average of these two numbers.

$\begin{array}{l} \frac{55 + 58}{2} = \frac{113}{2} \\ = 56.5 \end{array}$