Part 1: Shell Oil Company produces natural gas,gasoline,oil,and other chemical products.A manager of the credit card department for the company wanted to assess the monthly balance of credit card holders.An auditor selects a random sample of28accounts and finds that the mean owed is$79.00with a standard deviation of$23.65.At the0.10level of significance,is there evidence to suggest that the average monthly balance is less than$84.00?

Determine the rejection region.

Part 2: A study at the Harvard School of Public Health found that 40% of college students were binge drinkers.A student at the Univeristy of South Carolina plans to estimate the proportion of college students at that school who are binge drinkers.How large a random sample would she need to estimate it to within 0.04 with 95% confidence, if before conducting the study she uses the Harvard study results as a guideline.