document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1069519>Question 1069519</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A recent report indicated that 67% of teens 12 to 19 play a video game online at least once a week. How large of a sample would a researcher need to estimate the true proportion of teens 12 to 19 who play a video game online at least once a week within 3% with a 95% confidence level?\r<BR>\n" );
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document.write( "a) 844<BR>\n" );
document.write( "b) 4489<BR>\n" );
document.write( "c) 944<BR>\n" );
document.write( "d) 4144 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #684699 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=684699\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> half of the interval for a one sample proportion is z(0.975)sqrt{p*(1-p)/n}, and it equals .03<BR>\n" );
document.write( ".03=1.96*sqrt {(.67)(.33)/n}<BR>\n" );
document.write( "square both sides<BR>\n" );
document.write( ".0009=3.8416*(.67*.33)/n<BR>\n" );
document.write( ".0009n=0.8494 (I would not round but keep it on the calculator unrounded until the end.<BR>\n" );
document.write( "divide by .0009<BR>\n" );
document.write( "943.75.  Round upward to 944.<BR>\n" );
document.write( "C. </SPAN>\n" );
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