Question 245776
 A researcher is interested in estimating the noise levels in decibels at area urban hospitals. She wants to be 99% confident that her estimate is correct. If the standard deviation is 4.4, how large a sample is needed to get the desired information to be accurate within 0.65 decibels
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n = [z*s/E]^2
n = [2.576*4.4/0.65]^2
Round up to get whole-number "n".
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Cheers,
Stan H.