document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=472065>Question 472065</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A standard placement test has a mean of 115 and a standard deviation of 10. What is the minimum sample size required if we want to construct the 90% confidence interval with the margin of error 2 points?.<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 #323693 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=323693\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A standard placement test has a mean of 115 and a standard deviation of 10. What is the minimum sample size required if we want to construct the 90% confidence interval with the margin of error 2 points?.<BR>\n" );
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document.write( "ME = z*s/sqrt(n)<BR>\n" );
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document.write( "2 = 1.645*10/sqrt(n)<BR>\n" );
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document.write( "sqrt(n) = [1.645*10/2]<BR>\n" );
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document.write( "sqrt(n) = 8.225<BR>\n" );
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document.write( "n = 68 when rounded up<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
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