Question 581733
How large a sample should be taken if the desired margin of error is two minutes at a 95% level of confidence? 
n = [1.96*8/2]^2 = 61.47; rounded to n = 62
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How large a sample should be taken for a 99% level of confidence? Use a planning value for the population standard deviation of eight minutes.
n = [2.5758*8/2]^2 = 106.15; rounded to n = 107
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cheers,
Stan H.