1. For a new process with which the production personnel have little experience, neither the standard deviation nor the mean of the process is known.
Twenty different simple random samples, each with n 5 50, are to be drawn from the process, and a 90% confidence interval for the mean is to be constructed for each sample. What is the probability that at least 2 of the confidence intervals will not contain the popula- tion mean?
2. There were 904 new Subway Restaurants fran- chises opened during 2002. Suppose that Subway wished to survey a simple random sample of the new franchisees to find out what percentage of them were totally pleased with their relationship with the company. If Subway wanted to have 90% confidence in being within 3 percentage points of the population percentage who are pleased, how many of the new franchisees would have to be included in the sample?
Source: Subway.com. June 13, 2003.