Mean, Median, Mode and Range

In this chapter we’re going to look at mean, median, mode and range.

Mode is the common item in a list of items such as data of numbers.

The median is the middle value/item when a list of values is arranged in order.

The mean is the average, this is the total of items divided by the number of items there are.

The range describes how far from the smallest is from the biggest. This is why to find this value we have to subtract the biggest from the smallest to find the difference.
When working out the mean, median, mode and range it is a good idea to always rearrange the data into ascending order. Although for some don’t need to do this it is good practice to carry this out first to avoid any errors.

Example

Find the mean, median, mode and range of the following values.
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First we rearrange the data first as described above. When we rearrange we get;

Let’s find the mean first. Mean means the total of the data divide by the number of numbers in that data, so for the above data we get;

The mean is 2.21
Now let’s work out the median. Median means the middle value, so we get;

When two numbers happen to be the median we take the halfway of these numbers to be the median. In the above case the median is 2.5.
Now let’s find the mode. The mode is the most common value or the value that occurs more often.

The value which occurs more often in the list of data above is 3.
Range is the distance from lowest to the highest value, we find this by calculating the difference between the two. The highest or biggest number is 9 and the smallest number is -4 so we have;

So the range in the data above is 13.