How much work is G111?

Our student course evaluation forms ask students to report the average number of hours per week spent preparing. In Spring 2005, we got the following distribution (N = 30):

8-9 hrs 5
10-11 hrs 5
12-13 hrs 5
14-15 hrs 3
16-17 hrs 5
18-19 hrs 2
20-21 hrs 3
22 or more hrs 2

To save you the effort: this says that the median (and mean) was 13-14 hours per week. So be warned!