Question 232001
A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children. A sample of 150 was taken, and the mean amount spent was $225. Assuming a standard deviation equal to $50, find the 95% confidence interval for μ, the mean for all such families (show all work). 
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x-bar = 225
standard error = 1.96*[50/sqrt(150)] = 8
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95% CI: 225-8 < u < 225+8
95% CI: 217 < u < 233
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Cheers,
Stan H.