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Example 114


Example 114:  Butt-dialing 911 is a growing problem.  In New York City, a 2012 report stated that 40% of calls made to 911 were dialed in error from cell phones.    The report looked at a sample of 743,000 calls handled by NYC’s 911 operators.  Construct a 98% confidence interval estimate of the true proportion of NYC 911 calls that are made in error.  Before this report the mayor of NYC claimed that more than 45% of the calls made to 911 were due to “butt-dialing.” Did this report contradict the mayor’s claim?


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