The file Bulbs contains the life (in hours) of a sample of forty 20- watt compact fluorescent light bulbs produced by Manufacturer A and a sample of forty 20- watt compact fluorescent light bulbs produced by Manufacturer B. Use the following class interval widths for each distribution: Manufacturer A: 6,500 but less than 7,500, 7,500 but less than 8,500, and so on. Manufacturer B: 7,500 but less than 8,500, 8,500 but less than 9,500, and so on.
a. Construct percentage histograms on separate graphs and plot the percentage polygons on one graph.
b. Plot cumulative percentage polygons on one graph.
c. Which manufacturer has bulbs with a longer life— Manufacturer A or Manufacturer B? Explain.