The mean weight of four pieces of luggage is 76 pounds. If three of the pieces have weights of 72, 60, and 82 pounds, then what does the fourth piece of luggage weigh?

90 pounds.

The mean is all the numbers added together and divided by how many numbers there are.

So, we just add a certain number to 72, 60 and 82 and divide it by 4 till we get 76. Since 90 is the answer I'll use that.

72 + 60 + 82 + 90 = 304

Since there are 4 numbers we divide our total by 4.

304 / 4 = 76!

That makes the fourth piece of luggage 90 pounds.

Good luck on the rest of your questions! : D