document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=981166>Question 981166</A>: <I><SPAN STYLE=\"word-break: break-all;\"> You wish to estimate with a 95% confidence the population proportion of kids who say red is their favorite color. Estimate must be within 5% of population proportion. Find minimum sample size. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #602199 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=602199\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z = 1.96 is the critical value at 95% confidence<BR>\n" );
document.write( "E = 5% = 0.05 is the margin of error<BR>\n" );
document.write( "Since we don't know p, we make the conservative estimate that p = 0.5\r<BR>\n" );
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document.write( "n = p(1-p)(z/E)^2\r<BR>\n" );
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document.write( "n = 0.5(1-0.5)(1.96/0.05)^2\r<BR>\n" );
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document.write( "n = 384.16\r<BR>\n" );
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document.write( "n = 385 ... Round up to the nearest whole number.\r<BR>\n" );
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document.write( "The min sample size needed is 385. </SPAN>\n" );
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