Find the average: 15, 24, 39
(15 + 24 + 39) : 3 = 26
Find the mean of the following numbers: 28, 46, 71, 90, 110
(28 + 46 + 71 + 90 + 110) : 5 = 69
Find the sum of 6 numbers provided that their average is 54
54 x 6 = 324