document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1128740>Question 1128740</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me solve this problem.  \r<BR>\n" );
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document.write( "The standard IQ test has a mean of 97 and standard deviation of 17.  We want to be 95% certain that we within 5IQ points of the true mean.  Determine the required 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 #745221 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=745221\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> confidence interval is z*sigma sqrt (n). <BR>\n" );
document.write( "z=1.96, and CI is the +/- value, which is 5 here.<BR>\n" );
document.write( "5=1.96*17sqrt(n)<BR>\n" );
document.write( "square everything<BR>\n" );
document.write( "25=3.84*289/n<BR>\n" );
document.write( "n=3.8416*289/25=44.41 or sample size of 45<BR>\n" );
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