To easily find the mode, put the numbers in order from least to greatest
Which is, 1,2,4,4,7,7,7,7,9
Count how many times each number occurs. The number that occurs the most is the mode!
7 occurs the most! So the mode is 7.
Find the largest and smallest values in the set
They are 1 and 9.
Subtract the smallest value from the largest value to find the range
1 - 9 = 8
The range is 8.