1. A random sample of size 49 is drawn from a population with a standard deviation of 11. If only 18% of the time a sample mean greater than 325 is obtained, what is the mean of the population?
2.According to the Canadian Newspaper Association, the average daily circulation of The Globe and Mail based on 2007 figures is 337,387. Suppose the standard deviation is 8,160. Assume the paper's daily circulation is normally distributed.
(a) On what percentage of days would it surpass a circulation of 350,000?
(b) Suppose the paper cannot support the fixed expenses of a full-production setup if the circulation drops below 321,000. If the probability of this event occurring is low, the production manager might try to keep the full crew in place and not disrupt operations. How often will this event happen, based on the historical information?