Data was collected for 311 randomly selected 10 minute intervals. For each ten-minute interval, the number of people entering the atrium of a large mall were recorded. The data is summarized in the histogram below. 80 60 Frequency 40 20 80 90 100 110 120 130 Number of People in 10 min Q What is the class width for this histogram (and corresponding GFDT)? Note: Each class contains its lower class limit, but not its upper class limit. Class width =