SOLUTION: A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children. A sample of 120 was taken, and the mean amount spent was $225.43

Question 442346: A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children. A sample of 120 was taken, and the mean amount spent was $225.43. Assuming a standard deviation equal to $35.89, find the 95% confidence interval for mean, the mean for all such families.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A sample of 120 was taken, and the mean amount spent was $225.43. Assuming a standard deviation equal to $35.89, find the 95% confidence interval for mean, the mean for all such families.
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x-bar = 225.43
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E = 1.96*35.89/sqrt(120) = 6.4215
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95% CI: 225.43-6.4215 < u < 225.43+6.4315
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Cheers,
Stan H.
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