Question 230278
A researcher is interested in estimating the noise levels in decibels at area urban hospitals. She wants to be 90% confident that her estimate is correct. If the standard deviation is 4.8, how large a sample is needed to get the desired information to be accurate within 0.70 decibels? Show all work.
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n = [z*s/E]^2
n = [1.645*4.8/0.7]^2 = 127.24
Round Up to n = 128
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Cheers,
Stan H.