The average or arithmetic mean or mean of two or more quantities is equal to their sum divided by the number of those quantities.
Example 1:
The average of 22, 24, 28 & 34
(22+24+28+34) / 4 = 108 / 4 = 27
Example 2:
The average of 4 numbers is 17. The first 3 numbers are 12, 14, 18. Find the fourth number.
AVERAGE = (12+14+18+x) / 4 = 17
44 + x = 68
x = 68 – 44 = 24