SOLUTION: A survey of 36 "iPhone" owners showed that the purchase price has a sample mean of $450 with a sample standard deviation of $175.
a) Compute the 95% confidence interval for the
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Question 670665: A survey of 36 "iPhone" owners showed that the purchase price has a sample mean of $450 with a sample standard deviation of $175.
a) Compute the 95% confidence interval for the mean.
b) How large a sample is needed to estimate the population mean within $10 at a 99% confidence level?
Please show all work, calculations, and formulas!!
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A survey of 36 "iPhone" owners showed that the purchase price has a sample mean of $450 with a sample standard deviation of $175.
a) Compute the 95% confidence interval for the mean.
x-bar = 450
ME = 1.96*175/sqrt(6) = 9.5278
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95%CI: 450-9.5278 < u < 450+9.5278
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b) How large a sample is needed to estimate the population mean within $10 at a 99% confidence level?
n = [z*s/E]^2
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n = [2.5758*175/10]^2 = 2032 when rounded up
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Cheers,
Stan H.
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