Janet wanted to determine her average phone call length over 90 days. She collected the phone bills and randomly picked ten entries to look at. The phone call lengths, in minutes, are shown below. 3, 9, 17, 9, 11, 3, 11, 3, 17, 3

Assuming that the sample was representative of all the entries on the bills, what was the mean number of minutes over 90 days?

A. 7

B. 10

C. 8.6