Final answer:
Deshaun's math quiz results have a range of 8 and the mode is 9, which is the number that appears most frequently.
Step-by-step explanation:
Deshaun's math quiz results are 9, 9, 1, 9, 9, 2, 4, 9, 1. To find the range, we subtract the smallest number in the set from the largest number. The largest number is 9 and the smallest is 1, so the range is 9 - 1 = 8. The mode of a set of numbers is the number that appears most frequently. In this case, the number 9 appears most often, five times, so the mode is 9.