The file Bulbs contains the life (in hours) of a sample of forty 6-watt light emitting diode (LED) light bulbs produced by Manufacturer A and a sample of forty 6-watt LED light bulbs produced by Manufacturer B.

a. Construct a frequency distribution and a percentage distribution for each manufacturer, using the class interval widths for each distribution on page 57. Manufacturer A: 46,500 but less than 47,500; 47,500 but less than 48,500; and so on. Manufacturer B: 47,500 but less than 48,500; 48,500 but less than 49,500; and so on.

b. Construct cumulative percentage distributions.

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