Average
An average is a single number or value that best represents a set of data.
The type of average taken as most typically representative of a list of numbers is the arithmetic mean – the sum of the numbers divided by how many numbers are in the list.
To calculate the mean
1. Add up all the values.
2. Divide by the number of values.
Example:
The mean average of the numbers 2, 3, 4, 7, and 9.
(2+3+4+7+9 = 25) : 5 = 5
The average is 5.
Comparison of common averages of values { 1, 2, 2, 3, 4, 7, 9 } (https://en.wikipedia.org/wiki/Average)
|
Type |
Description |
Example | Result |
| Arithmetic mean | Sum of values of a data set divided by number of values: | (1+2+2+3+4+7+9) / 7 | 4 |
| Median | Middle value separating the greater and lesser halves of a data set | 1, 2, 2, 3, 4, 7, 9 | 3 |
| Mode | Most frequent value in a data set | 1, 2, 2, 3, 4, 7, 9 | 2 |
| Mid-range | The arithmetic mean of the highest and lowest values of a set | (1 + 9)/2 | 5 |
