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.