Answer:
(a) 15 students
(b) 3 minutes (by 4 students)
(c) 2 students
(d) 7 students
(e) Ordering this data from least to greatest:
0, 1, 2, 2, 3, 3, 3, 3, 5, 5, 7, 7, 9, 9, 11
The median number is 3.