document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=256946>Question 256946</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 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<BR>\n" );
document.write( "of longshoremen? (See U.S. News &World Report 123, no. 22 [December 8, 1997].)\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #188997 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=188997\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The U.S. Customs Service conducted a random check of Miami longshoremen and found that 36 of 50 had arrest records. <BR>\n" );
document.write( "(a) Construct a 90 percent confidence interval for the true proportion.<BR>\n" );
document.write( "sample proportion: 36/50 = 0.72<BR>\n" );
document.write( "standard error: 1.645*sqrt[0.72*0.18/50] = 0.0837...<BR>\n" );
document.write( "90% CI: 0.72-0.0837 < p < 0.72+0.0837<BR>\n" );
document.write( "90% CI: 0.6363 < p < 0.8037 <BR>\n" );
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document.write( "(b) Is the sample size large enough to be convincing? Explain.<BR>\n" );
document.write( "I'll leave that up to you.<BR>\n" );
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document.write( "(c) How would you select a random sample of longshoremen?<BR>\n" );
document.write( "I'll leave that up to you.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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