# Mode - GMAT Math Study Guide

## Definitions

• Mode - The value that appears most within a set of numbers.
For example, the mode of the set consisting of the numbers 2, 4, 3, 2, 8, 2 is 2 since the number two appears the most (i.e., three times).

## Calculating the Mode

Calculating the mode is a lot less complex than other mathematical calculations. In order to calculate the mode, tally up the number of times each number appears in a set. The mode is the number that appears the most often. A set of data can have more than one mode if there is a tie for the number that occurs most frequently.

Consider the following example:

Set S: 4, 2, 8, 9, 1, 4, 8, 4, 6, 2, 9, 5, 18

Create a tally of the frequency of each number

 Value Frequency (i.e., number of times value appears in Set S) 1 1 2 2 4 3 5 1 6 1 8 2 9 2 18 1

The number 4 is the mode since it appears the most frequently in Set S.

### Multiple Modes

A Set can also have multiple modes.

Set X: 2, 5, 6
This set is tri-modal since each of the three numbers appears the most often (i.e., one time).

Another Example:

Set N: 3, 5, 7, 3, 5
This set is bi-modal since both 3 and 5 appear twice, which is more than the other numbers.