document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1069498>Question 1069498</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A music industry researcher wants to estimate, with a 90% confidence level, the proportion of young urban people (ages 21 to 35 years) who go to at least 3 concerts a year. Previous studies show that 21% of those people (21 to 35 year olds) interviewed go to at least 3 concerts a year. The researcher wants to be accurate within 1% of the true proportion. Find the minimum sample size necessary.\r<BR>\n" );
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document.write( "a) 4142<BR>\n" );
document.write( "b) 663<BR>\n" );
document.write( "c) 945<BR>\n" );
document.write( "d) 4489 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #684742 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=684742\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The half interval, 0.01=z(0.95)*sqrt (0.21*0.79)/n<BR>\n" );
document.write( "square both sides<BR>\n" );
document.write( "0.0001=1.645^2*0.21*0.79/n<BR>\n" );
document.write( "n=3.8416*0.21*0.79/0.0001=4489.29, rounds to 4490.<BR>\n" );
document.write( "D  </SPAN>\n" );
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