This quiz works best with JavaScript enabled. Home > Ugc Net > Paper 1 > Research Stats > Confidence Intervals – Quiz 4 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Confidence Intervals Quiz 4 (18 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. The lifetime of a certain type of batter is known to be normally distributed with a standard deviation of 20 hours. A sample of 50 batteries had a mean lifetime of 120.1 hours. It is desired to construct a 99% confidence interval for the mean lifetime of this type of battery.What is the Confidence Interval to one decimal place? A) (114.56, 125.64). B) (114.5, 125.6). C) (112.8, 127.4). D) (112.82, 127.38). Show Answer Correct Answer: C) (112.8, 127.4). 2. An IQ test was given to a simple random sample of 75 students at a certain college. The sample mean score was 105.2. Scores on this test are known to have a standard deviation of 10. It is desired to construct a 90% confidence interval for the mean IQ scores of the students at the college.Find the Margin of Error to two decimal places. A) 1.90. B) 1.89. C) 1.899. D) 1.99. Show Answer Correct Answer: A) 1.90. 3. A researcher at a major hospital wishes to estimate the proportion of the adult population of the U.S. that has high blood pressure. How large a sample is needed in order to be 90% confident that the sample proportion will not differ from the true proportion by more than 5%? A) 302. B) 271. C) 164. D) 542. Show Answer Correct Answer: B) 271. 4. What is the margin of error for the interval (6.8, 12.9)? A) 3.05. B) 9.85. C) 6.8. D) 3.50. Show Answer Correct Answer: A) 3.05. 5. A random sample of 100 Woodrow students found that 53 of them were in possession of a pencil. Create a 90% confidence interval for this sample. A) (0.45, 0.61). B) (0.43, 0.63). C) (0.53, 0.63). D) None of above. Show Answer Correct Answer: A) (0.45, 0.61). 6. Which of the following is an example of an interval estimate? A) Statistic. B) Critical value. C) Point estimate. D) Confidence interval. Show Answer Correct Answer: D) Confidence interval. 7. Find the critical value zc necessary to form a 98% confidence interval. A) 0.5040. B) 2.05. C) 2.33. D) 0.8365. Show Answer Correct Answer: C) 2.33. 8. A random sample of 100 visitors to a popular theme park spent an average of $ 142 on the trip with a sample standard deviation of $ 47.50. Which of the following would be the 98% confidence interval for the mean money spent by all visitors to this theme park? A) ($ 130.96, $ 153.07). B) ($ 132.69, $ 151.31). C) ($ 140.88, $ 143.12). D) ($ 130.77, $ 153.23). Show Answer Correct Answer: A) ($ 130.96, $ 153.07). 9. A survey of 280 homeless persons showed that 63 were veterans. Construct a 90% confidence interval for the proportion of homeless persons who are veterans. A) (0.167 to 0.283). B) (0.184 to 0.266). C) (0.176 to 0.274). D) (0.161 to .289). Show Answer Correct Answer: B) (0.184 to 0.266). 10. Suppose that a confidence interval for hours worked by students was computed to be (8.82, 10.78). Which of these is a valid interpretation of this confidence interval? A) There is a 95% probability that the average number of hours worked by all students is between 8.82 and 10.78 hours. B) There is a 95% probability that a randomly selected student worked between 8.82 and 10.78 hours. C) We are 95% confident that the population average number of hours worked by all students is between 8.82 and 10.78 hours. D) We are 95% confident that the average number of hours worked by the students in our sample is between 8.82 and 10.78 hours. Show Answer Correct Answer: C) We are 95% confident that the population average number of hours worked by all students is between 8.82 and 10.78 hours. 11. Compute a 95% confidence interval:Hint:use p-hat formulaAfter watching a horror film, 34 out of 50 people reported problems getting to sleep. A) (.55, .81). B) (.571, .789). C) There is not enough information to compute a confidence interval. D) (.671, .689). Show Answer Correct Answer: A) (.55, .81). 12. You want to estimate, with 95% confidence, the proportion of households with pets. Your estimate must be accurate within 3% of the population proportion. No preliminary estimate is available. Find the minimum sample size needed. A) 1068. B) 1141. C) 1067. D) 3267. Show Answer Correct Answer: A) 1068. 13. Find the value of zc for a 90% confidence interval. A) 1.645. B) -1.96. C) 1.440. D) -1.598. Show Answer Correct Answer: A) 1.645. 14. What is the point estimator for the interval (-5, 13)? A) -5. B) 9.5. C) 10. D) 9. Show Answer Correct Answer: D) 9. 15. A local bank needs information concerning the savings account balances of its customers. A random sample of 13 accounts was checked. The mean balance was $ 686.75 with a sample standard deviation of $ 256.20. Find a 95% confidence interval for the true mean. A) ($ 525.59, $ 847.91). B) ($ 533.27, $ 840.23). C) ($ 513.14, $ 860.36). D) ($ 531.85, $ 841.65). Show Answer Correct Answer: D) ($ 531.85, $ 841.65). 16. You are given two sets of data measuring the same information, both with the same sample size. Set A has a larger Standard Error than Set B. If you were looking for a 99.8% Confidence Interval, which set would have a larger Margin of Error? A) I have no idea what you're asking me to do. B) Set A. C) Set B. D) Not enough information. Show Answer Correct Answer: B) Set A. 17. Does the interval (3, 14) support the claim that the mean of a data set is 2.9 A) Yes. B) No. C) Not enough information. D) None of above. Show Answer Correct Answer: B) No. 18. A ..... gives an interval of plausible values for the ..... A) Confidence interval, statistic. B) Point estimate, parameter. C) Point estimate, statistic. D) Confidence interval, parameter. Show Answer Correct Answer: D) Confidence interval, parameter. ← PreviousRelated QuizzesPaper 1 QuizzesUgc Net QuizzesConfidence Intervals Quiz 1Confidence Intervals Quiz 2Confidence Intervals Quiz 3Analysis Of Variance QuizChi Square QuizCoefficient Of Variation Discrete Serious And Continuous Serious QuizConcept Of Point And Interval Estimation QuizConcept Of Sampling And Other Concepts Related To Sampling Quiz 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books