Find the Median

When you have a whole load of information, it can be quite difficult to deal with.

For example, if I asked whether or not boys were taller than girls, you would have to do something to the data to be able to answer the question.

To do this we take averages.

 

What is an average?

An average is just one piece of information that represents all the other information in a data set.

There are three averages: mean, median and mode.

Each one has advantages and disadvantages.

In this worksheet, we are going to look at finding the median.

 

How do we find the median?

To find the median, we put all the data in order and find out what is in the middle.
 

Example 1:

Find the median of 2, 3, 5, 6, 1, 2, 3, 4, 5, 4, 6

 

Step 1: Put all the data in order

1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6

 

Step 2: Find the number in the middle

To do this, the easiest way is to cross off one from each end until we get to the middle.

1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6

This means  that the median is 4.

 

Example 2:

Find the median of 51, 28, 42, 31, 43, 57

 

Step 1: Put all the data in order

28, 31, 42, 43, 51, 57

 

Step 2: Find the number in the middle

If we do what we did before, we don't get a number in the middle, we get two!

28, 31, 42, 43, 51, 57

If this happens, we find out the number halfway between these two numbers in the middle.

Our median here is 42.5

 

Question time!