Triple A Battery Company is a majorbattery manufacturer of batteries and it produces three types ofbatteries (Type A, B, and C). The batteries are similar inconstruction but carry a different warranty period. Type A has a 36month warranty, Type B has a 48 month warranty, and Type C has a 60month warranty. Regardless of the warranty period, the standarddeviation of a battery’s life is 2.5 months. Let’s consider the 36month battery (Type A) for the following questions.
- If the average life of a Type A battery is 38 months, then whatproportion of the batteries will fail before the warrantyperiod?
- If a Type A battery is chosen at random, what is theprobability that battery will last at least 42 months? Assume themean life time of the battery is 38 months.
- Each year, the company establishes a budget for warranty costs.If a battery does not last until the warranty period expires, thenthey have to replace the battery at no charge to the customer. Thisyear they expect to replace 2% of the Type A batteries. What is thecutoff point, in months, for this 2%?
- Given the scenario in the previous problem, what would the meanlifetime have to be for the company to stay under budget for theType A batteries? In other words, what would the mean have to be ifonly 2% of the population is less than 36 months?
- The company has found that if their Type A batteries last atleast 6 months beyond the warranty period (44 months or more), thenthe customer is sure to buy their battery as a replacement when itfails. What portion of the customers can they count on as beingrepeat customers? Assume the mean life is 38 months.