In Exercises 3-8, decide whether the normal sampling distribution can be used. If it can be used, test the claim about the population proportion p at the given level of significance a using the given sample statistics. 3. Claim: p = 0.25; a = 0.05. Sample statistics: p = 0.239, n = 105 4. Claim: p 0.30; = 0.05. Sample statistics: p = 0.35, n = 500 a 5. Claim: p < 0.12; a = 0.01. Sample statistics: p = 0.10, n = 20 6. Claim: p > 0.125; a = 0.01. Sample statistics: p = 0.2325, n = 45 7. Claim: p 0.48; a = 0.10. Sample statistics: p = 0.40, n = 70 8. Claim: p = 0.80; a = 0.10. Sample statistics: p = 0.875, n = 16 Using and Interpreting Concepts ACTIVI Testing Claims In Exercises 9-14, (a) write the claim mathematically and identify Ho and Ha, (b) find the critical value(s) and identify the rejection region(s), (c) find the standardized test statistic, (d) decide whether to reject or fail to reject the null hypothesis, and (e) interpret the decision in the context of the original claim. If convenient, use technology to find the standardized test statistic. 9. Smokers A medical researcher says that at least 20% of U.S. adults are smokers. In a random sample of 200 U.S. adults, 18.5% say that they are smokers. At a = 0.01, is there enough evidence to reject the researcher's claim? (Adapted from U.S. National Center for Health Statistics) = 10. Do You Eat Breakfast? A research center estimates that no more than 40% of U.S. adults eat breakfast every day. In a random sample of 250 U.S. 0.01, is there enough adults, 41.6% say they eat breakfast every day. At a evidence to reject the researcher's claim? (Adapted from Harris Interactive) 11. Environmentally Conscious Consumers You are employed by an environmental conservation agency that recently claimed that more than 30% of U.S. consumers have stopped buying a certain product because the manufacturing of the product pollutes the environment. You want to test this claim. You randomly select 1050 U.S. consumers and find that 32% have stopped buying this product because of pollution concerns. At a = you support the agency's claim? (Adapted from Wirthlin Worldwide) 0.03, can 13. Finding a Real Estate Agent In your work for a real estate company, you find that in a sample of 1762 home buyers, 722 found their real estate agent through a friend. At a = 0.02, can you reject the claim that 44% of home buyers find their real estate agent through a friend? (Adapted from USA TODAY)