The caffeine content of 20 brands of regular coffee is shown below. 80 82 89 85 87 30 33 44 40 46 50 55 60 62 71 90 92 75 63 65. Thus, this job helps to construct a Frequency Distribution with a class interval of 10, starting with 30. It shows the class limits, class boundaries, class midpoints, class frequencies and class cumulative less than frequencies.