Then check by finding the standard deviations in Excel.

Set 1 Set 2
a. 3, 5, 6, 7, 9 2, 4, 6, 8, 10
b. 10, 14, 15, 16, 20 10, 11, 15, 19, 20
c. 2, 6, 6, 9, 11, 14 82, 86, 86, 89, 91, 94