Central tendency
Brief introduction
Central tendency is a measure of a certain value of a data set.
Mean
The mean is a form of central tendency that finds the value of the sum of any array of numbers divided by the amount of
numbers in it. It is the most common definition for average. For example, in an array of 6 numbers,
17, 82, 53, 36, 14
Mean = (17+82+53+36+14)/5
=202/5
=40.5
Median
The median, on the other hand, is a form of central tendency that finds the number in the middle of the array of numbers, and
is therefore the one based on order. For example, in this particular array of numbers,
17, 82, 53, 36, 14
The median would be the 53, which is the number in the middle of the array. We can also use the formula (n+1)/2 to
determine which number the median is. However, if the number of numbers in an array are even, we, although still use the
same formula, must find the mean of the two numbers in the centre, like this:
17, 82, 53, 36, 14, 62
(6+1)/2=3.5
Median = 3.5th number
= mean of 54 and 36
= (54+36)/2
= 90/2
=45
Mode
Mode is the form of central tendency that finds the most frequent number to appear. For example, in the above array of
numbers, there is no mode, as all numbers only appear once. However, if we were to add another 62,
17, 82, 53, 36, 14, 62, 62
The mode would be 62.