document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=126661>Question 126661</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/321462572/algebrahomeworkh>Elementary Statistics</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> A study of 420,095 Danish cell phone users found that 135 of them developed cancer of the brain or nervous system.  Prior to this study of cell phone use, the rate of such cancer was found to be 0.0340% for those not using cell phones. The data are from the Journal of the National Cancer Institute.\r<BR>\n" );
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document.write( "a. Use the sample data to construct a 95% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system.\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 #92791 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=92791\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A study of 420,095 Danish cell phone users found that 135 of them developed cancer of the brain or nervous system.  Prior to this study of cell phone use, the rate of such cancer was found to be 0.0340% for those not using cell phones. The data are from the Journal of the National Cancer Institute.\r<BR>\n" );
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document.write( "a. Use the sample data to construct a 95% confidence interval estimate of the percentage of cell phone users who develop cancer of the brain or nervous system.<BR>\n" );
document.write( "p-hat = 135/420095 = 0.0003213559 <BR>\n" );
document.write( "E = z*sqrt(pq/n) = 1.96*sqrt(0.034*0.0966/420,095)= 0.0001733<BR>\n" );
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document.write( "0.0001483559 <= p <= 0.00049466\r<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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