Three of four numbers have a sum of 22. If the average of the four numbers is 8, what is the fourth number?

Question

cas_fangirl_14 · Answer

The set of three is 22 ... the set of four is 4x8 or 32 ...

The 4th number is the difference in the sets ==> 10

akidwell133 · Answer

I don't quite understand how to do that. Can you show me how to do it step by step?

cas_fangirl_14 · Answer

First, you need to know how to find an average: Add up the numbers, and then divide that sum by the number of items you added. 

Since you know that the average is 8, and there are 4 items, just multiply those two numbers to get the sum they add up to, which is 32.

Because three of the numbers add up to 22, the missing number must be 10 by subtraction (32 minus 22).

akidwell133 · Answer

Thank you