What does average mean ? The average is a single number used to represent a set of numbers. Imagine you could pick a number that best describes all the data in a set, what number would you pick?
The number you pick would be the average. There are three types of average as shown below
The arithmetic mean
is the most frequently used average. It is found by adding all the
values in a set and then dividing by the number of values in the set.
Use the arithmetic mean when the set has no values that are too high or too small compared with the other values in the set.
Example #1:
What is the average of 12, 14, 10, and 16.
There are no values that are too big or too small. Therefore, we can use the arithmetic mean.
Arithmetic mean = (12 + 14 + 10 + 16) / 4 = 52/4 = 13
You can use the median
when the set of values has a couple of values that are much bigger or much smaller than most of the other values. It is found by looking for
the value in the middle in the set after you put the set in order from
least to greatest.
Example #2:
What is the average of 12, 14, 10, 50, and 7
Since 50 is way too big compared to the other values in the set, use the median to find the average.
7, 10, 12, 14, 50
The value in the middle is 12, so the average is 12.
Finally, you can use the mode when there are many identical values in the set. The mode is found by looking for the value(s) that you see the most.
Example #3:
What is the average of 10, 14, 10, 10, 7, 6, 7.
Since there are identical values in the set, the mode will give a better description of the average.
Looking at the set, we see that 10 is the value that occurs the most. Thus, 10 is the average.