Hi,
A study was conducted to estimate the mean amount spent on birthday gifts for a typical family having two children.
A sample of 180 was taken, and the mean $219.76. Assuming SD = $41.77,
find the 99%confidence interval for µ, the mean for all such families.
ME = 2.576[41.77/sqrt(180)]
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CI: 219.76-ME < u < 219.76 + ME