document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1192861>Question 1192861</A>: <I><SPAN STYLE=\"word-break: break-all;\"> You want to obtain a sample to estimate how much parents spend on their kids Christmas presents. Based on previous study, you believe the population standard deviation is approximately sigma = 30 dollars. You would like to be 99% confident that your estimate is within 9.8 dollar(s) of average spending on the birthday parties. How many moms do you have to sample? Do not round mid-calculation. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #825424 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=825424\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> error=z(0.995)*sigma/sqrt(n)<BR>\n" );
document.write( "9.8=2.5758*30/sqrt(n)<BR>\n" );
document.write( "square both sides<BR>\n" );
document.write( "96.04n=5966.77<BR>\n" );
document.write( "n=62.127 or 63<BR>\n" );
document.write( " </SPAN>\n" );
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