Answer:
12
Step-by-step explanation:
First put the set in order from least to greatest:
4, 5, 6, 9, 10, 11, 12, 15, 16
To find the range you subtract the largest number by the smallest number.
4, 5, 6, 9, 10, 11, 12, 15, 16
So 16 - 4 = 12
So the range is 12.