4. + 0/2 points I Previous Answers My Notes A university with a high water bill

Question

4. + 0/2 points I Previous Answers My Notes A university with a high water bill is interested in estimating the mean amount of time that students spend in the shower each day. In a sample of 11 students, the average time was 5.33 minutes and the standard deviation was 1.33 minutes. Using this sample information, construct a 99% confidence interval for the mean amount of time that students spend in the shower each day. Assume normality. a) What is the lower limit of the 99% interval? Give your answer to three decimal places b) What is the upper limit of the 99% interval? Give your answer to three decimal places. 6.360

Explanation / Answer

Here' answer to the questions below:

The t value for df = 11-1 = 10 is 3.169

The formula we use for LB and UB is Mean +/- t*Stdev/sqrt(n), therefore :

The lower limit is Mean - t*Stdev/sqrt(n) = 5.33 - 3.169*1.33/sqrt(11) = 4.059

The upper limit is Mean + Z*Stdev/sqrt(n) = 5.33 + 2.575*1.33/sqrt(11) = 6.362

Related Questions

Navigate

• Browse (All)
• Browse 4
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.