document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1182661>Question 1182661</A>: <I><SPAN STYLE=\"word-break: break-all;\"> SAT scores are distributed with a mean of 1,500 and a standard deviation of 286.<BR>\n" );
document.write( "You are interested in estimating the average SAT score of first year students at your college.<BR>\n" );
document.write( "If you would like to limit the margin of error of your confidence interval to 25 points with a 90 percent confidence, how many students should you sample?<BR>\n" );
document.write( "(Round up to a whole number of students) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #812782 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=812782\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> this is a z-CI<BR>\n" );
document.write( "error = z(0.975)*sigma/sqrt(n)<BR>\n" );
document.write( "25=1.645*286/sqrt(n)<BR>\n" );
document.write( "square both sides<BR>\n" );
document.write( "625=221342.02/n<BR>\n" );
document.write( "n=354.14 or 355 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );