#### All the members of a high school softball team were asked how many hours they studied in a typical week. The results are shown in the histogram below.

a. We can see from the histogram that four students studied around 5 hours per week. How many students studied around 15 hours per week?

b. How many students were there in total?

c. Suppose that the four students represented by the histogram bar centered at 5 had all studied exactly 5 hours, the five students represented by the next histogram bar had all studied exactly 10 hours, and so on. If you were to add up the study times for all of the students, what result would you get?

d. What is the mean study time for these students?