<PRE><B>Question 135787</B>
A careful count of 13,789 carcasses of bugs killed by “mosquito zappers” used in homes near water showed that only 18 were mosquitoes.
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p-hat = 18/13789 = 0.0013..
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E = 1.645*sqrt[0.0013*0.9987/13789] = 0.0005047633...
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(a) Construct a 90 percent confidence interval for the proportion of all zapped bugs that are mosquitoes. 
95% CI: p-hat - E &lt; p &gt; p-hat +E
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(b) Is a confidence interval really helpful in deciding whether the devices fulfill their purpose? Explain
I&#39;ll leave that to you.
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Cheers,
Stan H.</PRE>