# Exam: sampling distributions and estimation; hypothesis testing

Questions 1 to 20: Select the best answer to each question. Note that a question and its answers may be split across a page break, so be sure that you have seen the entire question and all the answers before choosing an answer. 1. A human resources manager wants to determine a confidence interval estimate for the mean test score for the next office-skills test to be given to a group of job applicants. In the past, the test scores have been normally distributed with a mean of 74.2 and a standard deviation of 30.9. Determine a 95% confidence interval estimate if there are 30 applicants in the group.A. 64.92 to 83.48B. 63.14 to 85.26C. 68.72 to 79.68D. 13.64 to 134.76 2. Consider a null hypothesis stating that the population mean is equal to 52, with the research hypothesis that the population mean is not equal to 52. Assume we have collected 38 sample data from which we computed a sample mean of 53.67 and a sample standard deviation of 3.84. Further assume the sample data appear approximately normal. What is the p-value you would report for this test?A. 0.0037B. 0.4963C. 0.0074D. 0.0041 3. A researcher wants to carry out a hypothesis test involving the mean for a sample of n = 20. While the true value of the population standard deviation is unknown, the researcher is reasonably sure that the population is normally distributed. Given this information, which of the following statements would be correct?A. The researcher should use the z-test because the population is assumed to be normally distributed.B. The t-test should be used because α and μ are unknown.C. The t-test should be used because the sample size is small.D. The researcher should use the z-test because the sample size is less than 30. 4. Which of the following statements about p-value testing is true?A. The p represents sample proportion.B. P-value testing uses a predetermined level of significance.C. The p-value is the lowest significance level at which you should reject H0D. P-value testing applies only to one-tail tests.