Question 216702
A university wants to estimate the average amount of money that students spend on textbooks in a semester. It takes a random sample of 45 students and finds that an average amount of money spent was $282 with a standard deviation of $21. Find a 95% confidence interval estimate for the true mean amount of money spent on textbooks in a semester.
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sample mean = 282
standard error = 1.96*[21/sqrt(45)] = 6.1358...
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95% CI: 282-6.1358 < u < 282 + 6.1358
95% CI: 275.86 < u < 288.14
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Cheers,
Stan H.