document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=287251>Question 287251</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 #208223 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=208223\">put this solution on YOUR website!</A><BR><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<BR>\n" );
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document.write( "n = [zs/E]^2<BR>\n" );
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document.write( "n = [2.3263*150/25]^2<BR>\n" );
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document.write( "n = 194.82<BR>\n" );
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document.write( "Round up to 195<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
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