SOLUTION: The U.S. Customs Service conducted a random check of Miami longshoremen and found that 36 of 50 had arrest records. (a) Construct a 90 percent confidence interval for the true prop

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Question 256946: The U.S. Customs Service conducted a random check of Miami longshoremen and found that 36 of 50 had arrest records. (a) Construct a 90 percent confidence interval for the true proportion. (b) Is the sample size large enough to be convincing? Explain. (c) How would you select a random sample
of longshoremen? (See U.S. News &World Report 123, no. 22 [December 8, 1997].)

Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
The U.S. Customs Service conducted a random check of Miami longshoremen and found that 36 of 50 had arrest records.
(a) Construct a 90 percent confidence interval for the true proportion.
sample proportion: 36/50 = 0.72
standard error: 1.645*sqrt[0.72*0.18/50] = 0.0837...
90% CI: 0.72-0.0837 < p < 0.72+0.0837
90% CI: 0.6363 < p < 0.8037
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(b) Is the sample size large enough to be convincing? Explain.
I'll leave that up to you.
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(c) How would you select a random sample of longshoremen?
I'll leave that up to you.
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Cheers,
Stan H.