document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1140115>Question 1140115</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A previous study of nickels showed that the standard deviation of the weight of nickels is 150 milligrams. How many nickels does a coin counter manufacturer need to weigh so that she can be 98% confident that her sample mean is within 25 milligrams of the true average weight of a nickel? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #760608 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=760608\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the error= z*sigma/sqrt(n)<BR>\n" );
document.write( "so 25=2.33*150/sqrt(n)<BR>\n" );
document.write( "25 sqrt(n)=349.5<BR>\n" );
document.write( "sqrt(n)=13.98<BR>\n" );
document.write( "n=195.44 or round to 196 </SPAN>\n" );
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