The range of a set of numbers is the difference between the largest and smallest numbers in the set.

In the given set: 4, 3, 11, 9, 6, 15, 19, 23, 27, 24, 21, 16

The largest number is 27, and the smallest number is 3.

Range = Largest number - Smallest number

Range = 27 - 3

Range = 24