Question 1.28

1.28 Reliability of household appliances.

You are writing an article for a consumer magazine based on a survey of the magazine’s readers. Of 13,376 readers who reported owning Brand A dishwashers, 2942 required a service call during the past year. Only 192 service calls were reported by the 480 readers who owned Brand B dishwashers.

  1. Why is the count of service calls (2942 versus 192) not a good measure of the reliability of these two brands of dishwashers?
  2. Use the information given to calculate a suitable measure of reliability. What do you conclude about the reliability of Brand A and Brand B?