The mean of 3 numbers is 7. The mean of 4 other numbers is 8. The mean of 5 other numbers is 11. What is the mean of all 12 numbers?
Then, the mean
To work out the mean (what we understand as the 'average') we do the following;
As with other formulae in this form, we have 3 ways in which it can be used.
Remember that we may add Totals , we may add Numbers , but we may NOT ADD MEANS!
The mean of 3 numbers is 7 .
The mean of 4 numbers is 8
The mean of 5 number is 11
We can add numbers:
We can add totals:
We can find the mean of the 12 numbers: