Question

For 4 weeks, William volunteered as a helper for swimming classes. The first week, he volunteered for 8 hours. He volunteered for 12 hours in the second week, and another 12 hours in the third week. The fourth week, he volunteered for 9 hours. For how many hours did he volunteer per week, on average?

Answer 1

(1/4)( 8 + 12 +12 + 9) = 41/4 = 10 1/4 hours average