document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1143470>Question 1143470</A>: <I><SPAN STYLE=\"word-break: break-all;\"> he standard iq test has a mean of 96 and a standard deviation of 14.  We want to be 90% certain that we are within 4 IQ points of the true mean.  Determine the required sample size.<BR>\n" );
document.write( "a,  1<BR>\n" );
document.write( "b.  6<BR>\n" );
document.write( "c.  34<BR>\n" );
document.write( "d.  130 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #764445 by </B><A HREF=/tutors/aboutme.mpl?userid=amarjeeth123><B>amarjeeth123(570)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=amarjeeth123><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=764445\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> We have,<BR>\n" );
document.write( "z=1.64 for a confidence interval of 90%<BR>\n" );
document.write( "sigma=14<BR>\n" );
document.write( "CI=4<BR>\n" );
document.write( "CI=z*sigma/sqrt(n)<BR>\n" );
document.write( "Plugging in the values we get,<BR>\n" );
document.write( "4=1.64*14/sqrt(n)<BR>\n" );
document.write( "sqrt(n)=(1.64*14/4)=5.74<BR>\n" );
document.write( "n=32.9 which is approximately 34.<BR>\n" );
document.write( "Answer=(c)34<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );