Annual starting salaries for college graduates with degrees in business administration are generally expected to be between $30,000 and $35,000 Assume that a 95% confidence interval estimate of the population mean annual starting salary is desired. a. What is the planning value for the population standard deviation? a= 1250 b. How large a sample should be taken if the desired margin of error is $300? Round your answers to next whole number. $150? $90? c. Would you recommend trying to obtain the $90 margin of error? Explain. No, the sample size would probably be too time consuming and costly