Question 11,12,13

11. A certain drug can be used to reduce the acid produced by the body and heal damage to the esophagus due to acid reflux. The manufacturer of the drug claims that more than 85% of patients taking the drug are healed within 8 weeks. In clinical trials, 230 of 355 patients suffering from acid reflux disease were healed after 8 weeks. Test the manufacturer's claim at a = 0.05 level of significance. a. Write both null and alternative. Indicate the tail. b. Find test statistics (show formula and final answer with two decimals) c. Find P-value (round to 4 decimal places) and compare it with a. Do you reject or fail to reject the null hypothesis? d. Write the conclusion in the contest of the problem e. Find a 95% confidence interval for p (write formula and final answer) f. Interpret your intervals. 12. Suppose the mean IQ score of people in a certain country is 105. Suppose the director of a college obtains a simple random sample of 32 students from that country and finds the mean IQ is 105.2 with a standard deviation of 12.7. Test the claim that the mean IQ score of people is more than 105 at the a = 0.05 level of significance. a. State the null and alternate hypotheses. b. Find test statistics (show formula and final answer with two decimals) C. Find P-value (round to 4 decimal places) and compare it with a. Do you reject or fail to reject the null hypothesis? d. Write the conclusion in the contest of the problem e . Find a 95% confidence interval for mean (write formula and final answer): f. Interpret your intervals. 13. To test the claim that o