Question 242433
Assuming a standard deviation of 6 hours, what is the required sample size if the error should be less than ½ hour with a 95% level of confidence?
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n = [z*s/E]^2

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n = [1.96*6/(1/2)]^2
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n = [1.96*12]^2
n = 553.19
Rounding up you get n = 554
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Cheers,
Stan H.