20.Volunteer Hours.Look at the graph at the bottom of p. 681 to answer the following questions.

If one American who participated in volunteer work was selected at random,

determine the empirical probability that the person volunteered:

a.between 1 and 2 hours(3 pts.)

b.more than 5 hours per week(3 pts.)

c.between 2 and 5 hours per week(3 pts.)