An automobile dealer has an inventory of 328 used cars. The mean mileage of these vehicles is

Question:

An automobile has an inventory of 328 used cars. The mean mileage of these vehicles is to be estimated. Previous experience suggests that the population standard deviation is likely to be about 12,000 miles. If a 90% confidence interval for the population mean is to extend 2,000 miles on each side of the sample mean, how large of a sample is required if simple random sampling is employed? Dealer
A dealer in the securities market is an individual or firm who stands ready and willing to buy a security for its own account (at its bid price) or sell from its own account (at its ask price). A dealer seeks to profit from the spread between the...