The RC and More Superstore decides to track customer complaints as part of their ongoing customer satisfaction improvement program. After collecting data for two months, their check sheet appears as follows:
Type of Problem Frequency (number of times)
Batteries not included 6
Literature not included in box 9
Items damaged when received 21
Parts missing 13
Unit not working 1
If they construct a Pareto chart, what is the cumulative percentage of the two leftmost bars?