Median
The median is the middle number. To calculate the median of any set of numbers, you need to write the numbers in order.
To find the median number:
- Put all the numbers in numerical order
- For an odd number of results, the median is the middle number
- For an even number of results, the median will be halfway between the two central numbers
Finding the median with an odd number of results
Find the median of this set of numbers:
\(21, 23, 27, 19, 24, 22, 24\)
Answer
Put the numbers in numerical order
\(19, 21, 22, 23, 24, 24, 27\)
Find the middle number
\(19, 21, 22, \textbf{23}, 24, 24, 27\)
The median is \(23\)
Question
Find the median of this set of numbers
\(4, 6, 8, 3, 8, 4, 7\)
Arrange the numbers in order:
\(3, 4, 4, 6, 7, 8, 8\) (The median is the fourth number)
The median is \(6\)
Finding the median with an even number of results
To find the median of the numbers: \(5, 11, 12, 4, 8, 21\)
Put the results in order:
\(4, 5, 8, 11, 12, 21\)
Find the two numbers in the middle:
\(8\) and \(11\).
We need to find the value which is halfway between them.
The median is therefore:
\((8 + 11) \div 2 = 9\cdot5\)
Question
Find the median of this set of numbers
\(16, 21, 13, 14, 18, 12, 20, 18, 21, 14\)
Arrange the numbers in order
\(12, 13, 14, 14, 16, 18, 18, 20, 21, 21\)
(The median is between the \(5th\) and \(6th\) numbers)
The median is halfway between \(16\) and \(18\)
The median is \(17\)
