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Annual starting salaries for college graduates with degrees in business administration are generally expected to be between $20,000 and $40,000 - Assume that a 95% confidence interval estimate of the population mean annual starting salary is desired. a. What is the planning valuelfor the population standard deviation? = b. How large a sample should be taken if the desired margin of error is $300 ? Round your answer to next whole number. $190? $130? c. Would you recommend trying to obtain the $130 margin of error? Explain