Three of four numbers have a sum of 22. If the average of the four numbers is 8, what is the fourth number? I have the answer but need to understand how to find it. Please?

Question

anonymous · Answer

When they say "the average of the four numbers is 8", you immediately know the sum of the 4 numbers is 4x8 or 32. Why?
Avg = Sum / 4    ..... Multiply both sides by 4 .....  Sum = 4*Avg

anonymous · Answer

3 of the numbers sum to 22
All 4 sum to 32

Just subtract 22 from 32 to get the last number

anonymous · Answer

Thank you so much!! I knew it couldn't be that hard...just wasn't clicking. :-)

anonymous · Answer

No problem. Many math teachers might use a lot more algebra and variables to explain it, but it's not really necessary