Answer questions 11-19 ODD ONLY.

In Exercises 9-12, construct the indicated confidence interval for the population mean u using (a) a t-distribution. (b) If you had incorrectly used a normal distribution, which interval would be wider? 9. c = 0.90, x = 12.5, s = 2.0, n = 6 10. c = 0.95, x = 13.4, s = 0.85, n = 8 the 11. c = 0.98, x = 4.3, s = 0.34, n = 14 12. c = 0.99, x = 24.7, s = 4.6, n = 10 0.42. 26 9 aszla.8 8 The margin of error bellfl muilsH Using and Interpreting Concepts Constructing Confidence Intervals In Exercises 13 and 14, you are given the sample mean and the sample standard deviation. Assume the variable noblud is normally distributed and use a t-distribution to construct a 95% confidence belout interval for the population mean u. What is the margin of error of p? If ste noBal convenient, use technology to construct the confidence interval. 13. Repair Costs: Microwaves In a random sample of five microwave ovens, the mean repair cost was $75.00 and the standard deviation was $12.50. (Adapted from Consumer Reports) 14. Repair Costs: Computers In a random sample of seven computers, the mean repair cost was $100.00 and the standard deviation was $42.50. (Adapted from Consumer Reports) 15. You did some research on repair costs of microwave ovens and found that the standard deviation is o = $15. Repeat Exercise 13, using a normal distribution with the appropriate calculations for a standard deviation that is sm bas as known. Compare the results. 16. You did some research on repair costs of computers and found that the standard deviation is o = $50. Repeat Exercise 14, using a normal ib Ismtor distribution with the appropriate calculations for a standard deviation that is known. Compare the results. Constructing Confidence Intervals In Exercises 17 and 18, you are given the sample mean and the sample standard deviation. Assume the variable is normally distributed and use a normal distribution or a t-distribution to construct a 90% confidence interval for the population mean M. If convenient, use technology to construct the confidence intervals.17. Waste Generated (a) In a random sample of 10 adults from the United States, the mean waste generated per person per day was 4.54 pounds and the standard deviation was 1.21 pounds. (b) Repeat part (a), assuming the same statistics came from a sample size of 500. Compare the results. (Adapted from U.S. Environmental Protection Agency) 18. Waste Recycled (a) In a random sample of 12 adults from the United States, the mean waste recycled per person per day was 1.46 pounds and the standard deviation was 0.28 pound. (b) Repeat part (a), assuming the same statistics came from a sample size of 600. Compare the results. (Adapted from U.S. Environmental Protection Agency)