Sara wanted to know the ages of the children on the school bus. She conducted a survey and her results are shown below:
To find the mean add all the ages together and divide by the total number of children.
If you type all those ages into a calculator it is easy to make an error.
It can be helpful to see these results displayed in a frequency table:
The frequency table shows us that there are six children aged , seven children aged , five children aged ... etc.
To find the sum of their ages, calculate:
The total number of children is
So, the mean age is
You could also put this information into a table like the one below:
Find the mean of the shoe sizes of pupils in Mrs Harris’ class:
Notice that the mean value does not have to be a whole number or an actual shoe size.