The instructor of a large math
class estimates that at the intended
level of difficulty, his undergraduate midterm
exams require on average 10 minutes for
graduate students in his department to
complete. If the average is longer than 10
minutes, then the exam is likely too hard and
needs to be revised. As usual, the
professor gathers his 20 teaching assistants in
a room to have them test out the exam. The dataset holds the times it took the grad students to complete the exam.