# The Mode

The mode of a set of numbers is the number which occurs most often.

In a set of data, there can be more than one mode. A set with two modes is bi-modal, a set with three modes is tri-modal, etc. There can also be a data set with no mode.

Example 1:

Find the mode of the set $\left\{4,5,7,7,9,11,11,11,12,14\right\}$

In the data set, the numbers $4,5,9,12$ and $14$ each occur once.

The number $7$ occurs twice and $11$ occurs three times.

So, the mode of the data set is $11$ .

Example 2:

Find the mode of the set $\left\{14,19,22,22,26,27,29,33,44,55,55\right\}$

In the data set, the numbers $14,19,26,27,29,33$ and $44$ each occur once.

The numbers $22$ and $55$ occurs twice.

In this case, the data set has two modes, so it is bi-modal.

The modes are $22$ and $55$ .

The mode can be used as a measure of central tendency of a data set.