A Sample of Nine Students Is Selected from Among the Students

Multiple Choice

A sample of nine students is selected from among the students taking a particular exam. The nine students were asked how much time they had spent studying for the exam and the responses (in hours) were as follows:
18, 7, 10, 13, 12, 16, 5, 20, 21
Estimate the mean study time of all students taking the exam. Round your answer to the nearest tenth of an hour if necessary.

A) 13 hours
B) 12.2 hours
C) 13.6 hours
D) It is not possible to estimate the population mean from this sample data