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.

a. Construct a frequency distribution and a percentage distribution for each manufacturer, using 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.

b. Construct cumulative percentage distributions.

c. Which bulbs have a longer life— those from Manufacturer A or Manufacturer B? Explain.