To find the range of a set of numbers, you subtract the smallest number from the largest number.
First, let's identify the smallest and largest numbers in your set:
- The numbers are: 90, 128, 91, 93, 120, 100, 95, 92, 85
- The smallest number is: 85
- The largest number is: 128
Now, subtract the smallest number from the largest number to find the range:
Range = Largest - Smallest
Range = 128 - 85
Range = 43
So, the range of the given set of numbers is 43.