Question 251566: a study was conducted to estimate the mean amount spent on christmas gifts for a typical family having two children, a sample size 150 was taken, and the mean amount spent was $225, assuming a standard deviation equal to $50, find a 95% cinfidence interval
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! a study was conducted to estimate the mean amount spent on christmas gifts for a typical family having two children, a sample size 150 was taken, and the mean amount spent was $225, assuming a standard deviation equal to $50, find a 95% confidence interval.
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sample mean = 225
standard error = invT(0.025 with df = 149)*50/sqrt(150) = 1.976*50/sqrt(150)
= 8.067
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95% CI: 225-8.067 < u < 225+8.067
95% CI: 216.933 < u < 233.067
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Cheers,
Stan H.
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