In a survey, 20 people were asked how many magazines they had purchased during the previous year. The results are shown below. Construct a histogram to represent the data. Use 4 classes with a class width of 10, and begin with a lower class limit of -.5. What is the approximate amount at the center? 6 15 3 36 25 18 12 18 5 30 24 7 0 22 33 24 19 4 12 9