How to find the Median Value
It's the middle number in a sorted list.
Median Value
The Median is the "middle number" (in a sorted list of numbers).
Half the numbers in the list will be less, and half the numbers will be greater.
How to Fin the Median Value
To find the Median, place the numbers you are given in value order
and find the middle number.
Look at these numbers:
3, 13, 7, 5, 21, 23, 39, 23, 40, 23, 14, 12, 56, 23, 29
If we put those numbers in order we have:
3, 5, 7, 12, 13, 14, 21, 23, 23, 23, 23, 29, 39, 40, 56
There are fifteen numbers. Our middle number will be the eighth
number:
3, 5, 7, 12,
13, 14, 21, 23, 23, 23, 23, 29,
39, 40, 56
The median value of this set of numbers is 23.
And you can see that "half the numbers in the list are less, and half the numbers are greater."
(Note that it didn't matter if we had some numbers the same in the list)
Two Numbers in the Middle
BUT, if there are an even amount of numbers things are
slightly different.
In that case we need to find the middle
pair of numbers, and then find the the value that would be half
way between them. This is easily done by adding them together
and dividing by two.
An example will help:
3, 13,
7, 5, 21, 23, 23, 40, 23, 14, 12, 56, 23, 29
If we put those numbers in order we have:
3, 5, 7, 12,
13, 14, 21, 23, 23, 23, 23, 29, 40, 56
There are now fourteen numbers and so we don't have just one middle number, we have a pair of middle numbers:
3, 5, 7, 12, 13, 14, 21, 23, 23, 23, 23, 29, 40, 56
In this example the middle numbers are 21 and 23.
To find the value halfway between them, add them together and
divide by 2:
21 + 23 = 44
44 ÷ 2 = 22
And, so, the Median in this example is 22.
(Note that 22 was not in the list of numbers ... but it is OK, because "half the numbers in the list are less, and half the numbers are greater.")
