4 8 9 CHAPTER 14 STATISTICAL INFERENCE: REVIEW OF CHAPTERS 12 AND 13 SECTION 1 MULTIPLE CHOICE QUESTIONS In the following multiple-choice questions, please circle the correct answer. 1. When the necessary conditions are met, a two-tail test is being conducted to test the difference between two population proportions. The two sample proportions are 1ˆ0.20p and2ˆ0.15p , and the standard error of the sampling distribution of 21ˆˆpp is 0.25. The calculated value of the test statistic will be: a. z = 2.0 b. z = 1.15 c. t = 2.0 d. t = 1.2 ANSWER: a 2. A random sample of size 15 taken from a normally distributed population resulted in a sample variance of 25. The upper limit of a 99% confidence interval for the population variance would be: a. 12.868 b. 92.032 c. 85.896 d. 75.100 ANSWER: c 490 Chapter Fou rteen 3. From a sample of 500 items, 30 were found to be defective. The point estimate of the population proportion defective will be: a. 0.06 b. 30.0 c. 16.667 d. None of the above ANSWER: a 4. A random sample of 20 observations taken from a normally distributed population revealed a sample mean of 65 and a sample variance of 16. The lower limit of a 90% confidence interval for the population mean would equal: a. 66.546 b. 63.454 c. 63.812 d. 66.188 ANSWER: b 5. In testing the hypotheses 0 :0.50Hp vs.1 :0.50Hp , at the 10% significance level, if the sample proportion is 0.56, and the standard error of the sample proportion is 0.025, then the appropriate conclusion would be: a. to reject 0H b. not to reject 0H c. to reject 1H d. to reject both 0H and 1H ANSWER: a 6. Two independent samples of sizes 35 and 40 are randomly selected from two normally distribu...
