Question: The owner of the hotel mentioned in Problem falls on hard times and dispenses with replacement of the bulbs. She notices that more than half of the bulbs have burned out before the advertised average lifetime of 3,280 hours and decides to sue the light bulb manufacturer for false advertising. Do you think she has a case?
Problem: Six thousand light bulbs light a large hotel and casino marquee. Each bulb fails completely at random, and each has an average lifetime of 3,280 hours. Assuming that the marquee stays lit continuously and bulbs that burn out are replaced immediately, how many replacements must be made each year on the average?