Answer:
You add them together and divide it by how many number there are.
Explanation:
For example lets say we need to find the average of 12, 15, 18, and 24.
You would do 12+15+18+24
You will get a sum of 69
Then since there are 4 numbers you do 69 divided by 4 and get a quotients of 17.25.
Therefore 17.25 is the average of all four numbers.