The range of a set of numbers is the difference between the highest and lowest values in the set. In other words, it is the spread or variation of the data. To find the range, you subtract the smallest number from the largest number in the set.
Range = (Largest Number) - (Smallest Number)
Find the range of the following set of numbers: 5, 8, 3, 12, 7
Largest Number = 12
Smallest Number = 3
Range = 12 - 3 = 9