document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1002176>Question 1002176</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 3.An anthropologist finds bone that her instruments measure it as  0.824% of the amount of Carbon-14 the bones would have contained when the person was alive. How long ago did the person die?<BR>\n" );
document.write( "The half life of carbon 14 is 5,730 years. Round your answer to the nearest thousand. <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #619185 by </B><A HREF=/tutors/aboutme.mpl?userid=fractalier><B>fractalier(6550)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=fractalier><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=fractalier><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=619185\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> For a half-life problem, the amount remaining at some time t is A(t).<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%28t%29=Ao%281%2F2%29%5E%28t%2F5730%29 ALIGN=MIDDLE  ALT=\"A%28t%29=Ao%281%2F2%29%5E%28t%2F5730%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "In your problem, you are given the ratio of A(t)/Ao.<BR>\n" );
document.write( "Thus<BR>\n" );
document.write( ".00824=(1/2)^(t/5730)<BR>\n" );
document.write( "log(.00824) = (t/5730)log(1/2)<BR>\n" );
document.write( "so that<BR>\n" );
document.write( "t = 5730(log(.00824)/log(.5)) = 39670 years or 40,000 years old </SPAN>\n" );
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