# Which of the following is a point estimate for the population mean (µ)?

1. Which of the following is a point estimate for the population mean (?)? A. ? B. ??? C. x/n D. s 2. When a confidence interval for a population mean is constructed from sample data, __________. A. We can conclude that the population mean is in the interval B. We can conclude that the population mean is not in the interval C. We can conclude, for an infinite number of samples and corresponding confidence intervals, that the population mean is in a stated percentage of the intervals D. We cannot make any inferences 3. A random sample of 42 college graduates revealed that they worked an average of 5.5 years on the job before being promoted. The sample standard deviation was 1.1 years. Using the 0.99 degree of confidence, what is the confidence interval for the population mean? A. 5.04 and 5.96 B. 5.06 and 5.94 C. 2.67 and 8.33 D. 4.40 and 6.60 4. A research firm wants to compute an interval estimate with 90% confidence for the mean time to complete an employment test. Assuming a population standard deviation of three hours, what is the required sample size if the error should be less than a half hour? A. 196 B. 10 C. 98 D. 16 5. A survey of households in a small town showed that in 500 of 1,200 sampled households, at least one member attended a town meeting during the year. Using the 95% level of confidence, what is the confidence interval for the proportion of households represented at a town meeting? A. [0.417, 0.427] B. [0.417, 0.445] C. [0.400, 0.417] D. [0.389, 0.445] 6. A university surveyed recent graduates of the English Department for their starting salaries. Four hundred graduates returned the survey. The average salary was \$25,000. The population standard deviation was \$2,500. What is the 95% confidence interval for the mean salary of all graduates from the English Department? A. [\$22,500, \$27,500] B. [\$24,755, \$25,245] C. [\$24,988, \$25,012] D. [\$24,600, \$25,600] Questions 7 – 8: The average cost of tuition and room and board at a small private liberal arts college is reported to be \$8,600 per term, but a financial administrator believes that the average cost is higher. A study conducted using 350 small liberal arts colleges showed that the average cost per term is \$8,745. The population standard deviation is \$1,200. Let ? = 0.05. 7. What are the null and alternative hypotheses for this study? A. H0: ? ? \$9,000; H1: ? > \$9,000 B. H0: ? ? \$9,000; H1: ? < \$9,000 C. H0: ? ? \$8,600; H1: ? > \$8,600 D. H0: ? ? \$8,600; H1: ? < \$8,600 8. What is the p-value for this test? A. 0.0001 B. 0.0119 C. 0.0500 D. 0.9881 9. Based on the Nielsen ratings, the local CBS affiliate claims its 11 p.m. newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station. What is the sample proportion? A. 0.41 B. 0.36% C. 0.41% D. 0.36    _________________________________________________________________________________________ 