8. A particular poll tracks daily the percentage of Americans who approve or disapprove of the...

8. A particular poll tracks daily the percentage of Americans who approve or disapprove of the performance by President 1. Daily results are based on random telephone interviews with approximately 1300 national adults. The poll reports that 49% of adults approve of President 1. The same poll reported an approval rating of 50% for President 2. A news anchor remarks that "President 1 doesn't even get as much approval as President 2 did." Is there evidence that this difference is real? State and test the appropriate hypotheses. Check conditions.

A. What is the value of the test statistic? (Round to two decimal places as needed.)

9. It the 1980s, it was generally believed that congenital abnormalities affected about 8% of a large nation's children. Some people believe that the increase in the number of chemicals in the environment has led to an increase in the incidence of abnormalities. A recent study examined 366 randomly selected children and found that 37 of them showed signs of an abnormality. Is this strong evidence that the risk has increased? (Consider a P-value of around 0.05 to represent reasonable evidence.)

A. What is the P-value? (Round to three decimal places as needed)

10. A magazine is considering the launch of an online edition. The magazine plans to go ahead only if it is convinced that more than 20% of current readers would subscribe. The magazine contacted a simple random sample of 500 current subscribers, and 108 of those surveyed expressed interest. What should the magazine do?

A. What is the P-value of the test statistic? (Round to three decimal places as needed.)

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orchestra answered 1 year ago

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