Annual starting salaries for college graduates with degrees in business administration are generally expected to be between 160,000 and 300,000. Assume that a 95% confidence interval estimate of the population mean annual starting salary is desired. Use of Excel is optional.

1. Using range divided by 4 as a rough approximation of the population standard deviation. Calculate this number.
2. How large a sample should be taken if the desired margin of error is 2000? 500?
3. Would you recommend trying to obtain a 200 margin of error? Explain.