Chapter 8 Homework: Confidence Intervals for One Sample, Quizzes of Statistics

Download Chapter 8 Homework: Confidence Intervals for One Sample and more Quizzes Statistics in PDF only on Docsity! 1. Question 1 1/1 True or False? The sample mean is a point estimate for the population mean. 1. T True 2. F False 2. Question 2 1/1 What is the generic format of a confidence interval? Hide answer choices  1. (Point estimate - margin of error, Point estimate + margin of error) 2. (Margin of error - point estimate, Margin of error + point estimate) 3. (Confidence level - margin of error, Confidence level + margin of error) 4. (Point estimate - confidence level, Point estimate + confidence level) 3. Question 3 1/1 What is the purpose of a confidence interval? Hide answer choices  1. To find a range of numbers that we think contains the unknown population parameter 2. To find a range of numbers that we think contains the sample statistic 3. To find a range of numbers that we think contains the margin of error 4. To find a range of numbers that we think contains the confidence level 4. Question 4 1/1 What does "95% confidence" mean for a confidence interval? Hide answer choices  1. If we took many samples and calculated a 95% confidence interval each time, about 95% of the intervals would contain the statistic. 2. The confidence interval is within 95% of the population parameter. 3. If we took many samples and calculated a 95% confidence interval each time, about 95% of the intervals would contain the parameter. 4. The confidence interval is within 95% of the sample statistic. What is the low end of a 95% confidence interval for the mean mercury content of all fish in the Kentucky River? Round your answer to 4 decimal places. Your Answer: 0.2376 12. Question 12 1/1 In a random sample of 10 fish from the Kentucky River, the mean mercury content was determined to be 0.287 parts per million (ppm) with a standard deviation of 0.069 ppm. What is the high end of a 95% confidence interval for the mean mercury content of all fish in the Kentucky River? Round your answer to 4 decimal places. Your Answer: 0.3364 13. Question 13 1/1 In a random sample of 10 fish from the Kentucky River, the mean mercury content was determined to be 0.287 parts per million (ppm) with a standard deviation of 0.069 ppm. What is the margin of error of a 95% confidence interval for the mean mercury content of all fish in the Kentucky River? Round your answer to 4 decimal places. Your Answer: 0.0494 14. Question 14 1/1 We use the t distribution rather than the normal distribution when calculating a confidence interval for a mean because we are using the sample standard deviation, which we do know, in place of the population standard deviation, which we do not know. 15. Question 15 1/1 Suppose a 99% confidence interval for the proportion of Kentuckians who support a new law is (0.2473, 0.3199). Interpret this confidence interval. Hide answer choices  1. There is a 99% chance that the proportion of all Kentuckians who support the new law is between 0.2473 and 0.3199. 2. We are 99% confident that the proportion of all Kentuckians who support the new law is between 0.2473 and 0.3199. 3. There is a 99% chance that the proportion of Kentuckians in our sample who support the new law is between 0.2473 and 0.3199. 4. We are 99% confident that the proportion of Kentuckians in our sample who support the new law is between 0.2473 and 0.3199.