The file Bulbs contains the life (in hours) of a sample of 40 100-watt light bulbs produced by Manufacturer A and a sample of 40 100-watt light bulbs produced by Manufacturer B. The following table shows these data as a pair of ordered arrays:
a. Construct a frequency distribution and a percentage distribution for each manufacturer, using the following class interval widths for each distribution:
Manufacturer A: 650 but less than 750, 750 but less than 850, and so on.
Manufacturer B: 750 but less than 850, 850 but less than 950, and so on.
b. Construct cumulative percentage distributions.
c. Which bulbs have a longer life-those from Manufacturer A or Manufacturer B? Explain.