4. Which of the following is the rejection region if the level of significance is 5%, right-tailed test will be utilized, n 40 and the population variance is known? A. below t =-1.721 B. above t =1.721 C. below z = -1.645 D. above z = 1.645 5. Which of the following is the rejection region if the level of significance is 5%, right-tailed test will be used, n 23, and the population variance is unknown? A. below t =-1.717 B. above t = 1.717 C. below z =-1.645 D. above z = 1.645 6. What is the rejection region given the following: right-tailed test, the population variance is known, 1% level of significance? A C. below z =-2.33 and above z = 2.33 D. below t = -2.33 and above t = 2.33 A. above z = 2.33 B. below z =-2.33 7. Which of the following is the rejection region if the level of significance is 5%, left-tailed test will be utilized, n 23, and the population variance is unknown? A. below t = -1.717 B. above t = 1.717 C. below z = -1.645 WNA D. above z = 1.645