The Eks Survey Company employs 2000 people to conduct telephone surveys. Because many people don't like to answer such surveys, many "hang-ups" (whereby the person hangs up without completing the survey) occur. The owner of Eks wants to determine the mean number of "hang-ups" per employee on a particular day, using 95% confidence level. He samples 36 employees, and finds that the mean number of "hang-ups" on that day was 38.6. Suppose that the standard deviation of the number of "hang-ups" for all employees is 20.4 What is the value of the margin of error? (round to four decimal places)