In the 2011 CFO Outlook survey done by Bank of America, 801 CFOs (chief financial officers) of American manufacturing and services companies were randomly chosen and asked about their views of the economy. In the sample, 64% expected revenue growth for their companies in the upcoming year. Forty seven percent expected their companies to hire additional employees during the upcoming year (source: corpbankofamerica.com). Using these sample results,
a. Build a 95% confidence interval estimate of the proportion of all CFOs who would expect revenue growth for their companies during the upcoming year.
b. Build a 95% confidence interval estimate of the proportion of all CFOs who would expect that their companies will hire additional employees during the upcoming year.