A research center claims that at most 75% of U.S. adults think that drivers are safer using hands-free cell phones instead of using hand-held cell phones. In a random sample of 150 U.S. adults, 77% think that drivers are safer using hands-free cell phones instead of hand-held cell phones. At α = 0.01, is there enough evidence to reject the center’s claim?
(a) Identify the claim and state H0 and Ha,
(b) Find the critical value(s) and identify the rejection region(s),
(c) Find the standardized test statistic z,
(d) Decide whether to reject or fail to reject the null hypothesis,
(e) Interpret the decision in the context of the original claim. If convenient, use technology. |

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