# Math Test Bus2023

2716 Words11 Pages
Practice Test 4 –Bus 2023 Directions: For each question find the answer that is the best solution provided. There is only one correct answer. 1. For a sample size of 30, changing from using the standard normal distribution to using the t distribution in a hypothesis test, a. will result in the rejection region being smaller b. will result in the rejection region being larger c. would have no effect on the rejection region d. Not enough information is given to answer this question. ANSWER: a -recall that all the t-values are larger than the z-values so it makes it more difficult to reject the null. 2. Read the t statistic from the table of t distributions and circle the correct answer. A two-tailed test, a sample of 20 at a .20 level of significance; t = a. 1.328 b. 2.539 c. 1.325 d. 2.528 ANSWER: a -go to the t-dtistrubution and use α=0.20 or confidence of 80% and use dof=19 3. Read the t statistic from the table of t distributions and circle the correct answer. A one-tailed test (upper tail), a sample size of 18 at a .05 level of significance t = a. 2.12 b. 1.734 c. -1.740 d. 1.740 ANSWER: d -same process but now go to one tailed α=0.05 and dof = 17 4. Read the t statistic from the table of t distributions and circle the correct answer. A one-tailed test (lower tail), a sample size of 10 at a .10 level of significance; t = a. 1.383 b. -1.372 c. -1.383 d. -2.821 ANSWER: c -see previous Exhibit 9-4 A random sample of 16 students selected from the student body of a large university had an average age of 25 years and a standard deviation of 2 years. We want to determine if the average age of all the students at the university is significantly different from 24. Assume the distribution of the population of ages is normal. 5.