1. A random sample of 144 with a mean of 300 and a standard deviation of 100 is taken from a population of 5000. Find an interval estimate for µ such that we are 90% confident that the interval includes µ.
2. find (a) the 95% and (b) the 99% confidence intervals. (c) What do the answers to parts a and b indicate?
3. A random sample of 400 is taken out of the more than 100,000 army recruits in a particular year. The average weight for the sample of army recruits is 170 lb, and the standard deviation of the entire population of army recruits is 40 lb. Find the 90% confidence interval for the mean weight of the population of army recruits.