21-22. Scenario:A pharmaceutical company says that the efficacy rate of their medicine is90% and the standard deviation is 3%. A sample of 400 volunteers from a city reveals that the efficacy rate is 88% with a standard deviation of 3%. At 1% significance level, check the veracity of the statement of the company. 21. Which of the following illustrations best describes the rejection region for given level of significance? O a O b 2 2 O c Od22. What is the * teststatistic? 23-24. Scenario:According to a guidance counselor, an average student spent less than 6 hours each day for school works. A sample of 100 students in a certain school reveals that the mean hours spent of the students is 5.5 hours with a standard deviation of 0.8. Determine whether the claim of the guidance counselor is correct with 95% confidence level. 23. Which of the following illustrations best * describes the rejection region for given level of significance? ----------------- a -2 -I n I 2 2 a - ::::::: aaaaaaaa ................. 24. What is the * teststatistic? 25. What is the teststatistic if p=3%; X=3.4%; s=0.5%; and n=15