In study of 500 executives, 315 stated that their company informally monitored social networking sites to stay on top of information related to their company.
a. Develop a 95% confidence interval for proportion of companies that informally monitor social networking sites.
b. Interpret interval constructed in a.
c. If you want to develop a follow up study to within plus/minus 0.01 with 95% confidence, how many executives would you survey?