Solution_Case Study_Business Statistics_2024-MANCOSA

Business Statistics Case Study solved! 1. The customer-care division of a large departmental store specializing in electrical appliances received several complaints in the past year. The time taken to resolve the complaints was variable. The accompanying table gives the number of days between the receipt and resolution of 30 randomlyselected complaints 12 23 5 20 11 2. You are given that a certain brand of audio speakers has an average trouble-free lifespan of 7.5 years with a standard deviation of 30 months. Assume that the lifetimes of individual speakers in the sample are normally distributed. i. What is the probability that a randomly selected audio speaker will work for more than 9 years without any trouble? ii. Twelve audio speakers of this brand are purchased by a company for 12 of its employees. What is the probability that exactly 7 out of the 12 audio speakers purchased by the company will work for over 9 years without any problem?