:8. Solution. The units on the horizontal line are in hundreds
of jelly beans. The class interval 3-5, representing people who
reported consuming
a. at least 300 but no more than 400 jelly beans
b. at least 400 but no more than 500 jelly beans,
is two units long. The rectangle with base equal to this class
interval should be 20%, so its height should be 20/2 = 10 percent
per unit.