Test 10B AP Statistics

Test 10B AP Statistics Name: Directions: Work on these sheets. Answer completely, but be concise. A normal probability table is attached. Part 1: Multiple Choice. Circle the letter corresponding to the best answer. 1. The value of z* required for a 70% confidence interval is (a) -0.5244 (b) 1.036 (c) 0.5244 (d) 0.6179 (e) The answer can’t be determined from the information given. (f) None of the above. The answer is . 2. A significance test allows you to reject a hypothesis H0 in favor of an alternative Ha at the 5% level of significance. What can you say about significance at the 1% level? (a) H0 can be rejected at the 1% level of significance. (b) There is insufficient evidence to reject H0 at the 1% level of significance. (c) There is sufficient evidence to accept H0 at the 1% level of significance. (d) Ha can be rejected at the 1% level of significance. (e) The answer can’t be determined from the information given. 3. A 95% confidence interval for the mean  of a population is computed from a random sample and found to be 9 ± 3. We may conclude that (a) There is a 95% probability that  is between 6 and 12. (b) There is a 95% probability that the true mean is 9 and a 95% chance the true margin of error is 3. (c) If we took many, many additional random samples and from each computed a 95% confidence interval for  , approximately 95% of these intervals would contain  . (d) If we took many, many additional random samples and from each computed a 95% confidence interval for  , 95% of them would cover the values from 6 to 12. (e) All of the above. 4. A 95% confidence interval for the mean reading achievement score for a population of third grade students is (44.2, 54.2). Suppose you compute a 99% confidence interval using the same information. Which of the following statements is correct? (a) The intervals have the same width. (b) The 99% interval is shorter. (c) The 99% interval is longer. (d) The answer can’t be determined from the information given. (e) None of the above. The answer is . 5. Which of the following are correct? I. The power of a significance test depends on the alternative value of the parameter. II. The probability of a Type II error is equal to the significance level of the test. III. Type I and Type II errors only make sense when a significance level has been chosen in advance. (a) I and II only (b)I and III only (c) II and III only (d) I, II, and III (e) None of the above gives the complete set of true responses. 6. In a test of H0: µ = 100 against Ha: µ  100, a sample of size 80 produces z = 0.8 for the value of the test statistic. The P-value of the test is thus equal to: (a) 0.20 (b) 0.40 (c) 0.29 (d) 0.42 (e) 0.21