document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1151506>Question 1151506</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A researcher wishes to estimate the proportion of adults who have​ high-speed Internet access. What size sample should be obtained if she wishes the estimate to be within 0.04 with 95​% confidence if<BR>\n" );
document.write( "​(a) she uses a previous estimate of 0.52​?<BR>\n" );
document.write( "​(b) she does not use any prior​ estimates?<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 #773280 by </B><A HREF=/tutors/aboutme.mpl?userid=rothauserc><B>rothauserc(4718)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rothauserc><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=rothauserc><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=773280\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Margin of error(ME) = 0.04<BR>\n" );
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document.write( "critical value(CV) for a 95% confidence is 1.96<BR>\n" );
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document.write( "sample size(n) = ( CV^2 * p * (1-p) ) / ME^2<BR>\n" );
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document.write( "(a) n = ( 1.96^2 * 0.52 * (1-0.52) ) / 0.04^2 = 599.2896 is approximately 600<BR>\n" );
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document.write( "(b) when proportion is not known use p = 0.50<BR>\n" );
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document.write( "n = ( 1.96^2 * 0.50 * (1-0.50) ) / 0.04^2 = 600.25 is approximately 601<BR>\n" );
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