Question 135301
A random sample of 76 four-year-olds attending day care centers showed that the yearly tuition averaged $3648.  The standard deviation of the sample was $630 and the sample size was 50.  Find the 90% confidence interval of the true mean.
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Note: you gave two numbers for the sample size: 76 and 50. I chose n=50.
x-bar = 3648
standard error = E = 1.645 * [630/sqrt(50)]= 146.56
CI: x-bar - E < mu < x-bar + E
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Cheers,
Stan H.