SOLUTION: Determine the sample size required to estimate a population mean to within 10 units given that the population standard deviation is 45. A confidence level of 90% is judged to be ap

Question 438681: Determine the sample size required to estimate a population mean to within 10 units given that the population standard deviation is 45. A confidence level of 90% is judged to be appropriate.
id really like to know how to do this and not just the answer. thanks in advance
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Determine the sample size required to estimate a population mean to within 10 units given that the population standard deviation is 45. A confidence level of 90% is judged to be appropriate.
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Since E = zs/sqrt(n)
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n = [zs/E]^2
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n = [1.645*45/10]^2 = 55 when rounded up
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Cheers,
Stan H.
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