📖Definition
The Mean, Median and Mode are all types of average. The Range tells you how spread out a set of data is. All of them are 'statistics' that summarise sets of data.
Mean
The Mean of a set of numbers is what is commonly known as the Average
To calculate it use the formula:
Sum of all Items ÷ Number of Items
Median
The Median of a set of data is the Middle Value.
Put the data in order from smallest to largest. If there's an odd number of items (2n+1), the Median is the value of the nth item.
If there's an even number (2n), the Median lies halfway between the nth and (n+1)th items.
Mode
The Mode is the value that appears most often in a set of data. It is also referred to as the Modal Value.
If two or more values are the most common, then there will be two or more Modal Values
It often helps to find the mode if you put the data in order first.
Range
The Range of a set of data is the difference between its largest and smallest values.
To calculate it, put the data in order and then subtract the smallest value from the largest.
✏️Example
Find the Mean, Median, Mode and Range of the data set:
5, 0, 1, 3, 8, 1, 3, 0, 2, 4, 8, 0, 3, 1, 0
✅Solution
The Mean is the sum of all the data divided by the number of pieces of data.
Mean = (5+0+1+3+8+1+3+0+2+4+8+0+3+1+0)÷15 = 39/15 = 2.6
For the Median, we need to put the data in numerical order.
0, 0, 0, 0, 1, 1, 1, 2, 3, 3, 3, 4, 5, 8, 8
There are 15 items so the 8th one in order is the Median ie.2
With the data in order it's easy to see the Mode is 0
0, 0, 0, 0, 1, 1, 1, 2, 3, 3, 3, 4, 5, 8, 8
There are 4 occurrences of 0 so that is the Mode
And with the data in order it's easy to find the range as well, it's 8 - 0 = 8