A study of the career paths of hotel general managers sent questionnaires to an SRS of 280 hotels belonging to major U.S. hotel chains. There were 157 responses. The average time these 157 general managers had spent with their current company was 13.28 years. (Take it as known that the standard deviation of time with the company for all general managers is 3 years.) (a) Find the margin of error for an 80% confidence interval to estimate the mean time a general manager had spent with their current company:  years (b) Find the margin of error for a 99% confidence interval to estimate the mean time a general manager had spent with their current company:  years

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