document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1112194>Question 1112194</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How long would n $800 investment take to earn $160 at a rate of 5% annually?\r<BR>\n" );
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document.write( "What is the interest rate if you earned $504 on an $1800 investment for 4 years?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #727284 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=727284\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> It would then be $960<BR>\n" );
document.write( "960=800(1+.05)^n<BR>\n" );
document.write( "divide by 800 both sides<BR>\n" );
document.write( "1.2=1.05^n<BR>\n" );
document.write( "ln 1.2=n ln 1.05<BR>\n" );
document.write( "n=ln 1.2/ln 1.05=3.11 years\r<BR>\n" );
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document.write( "2304=1800(1+r)^4<BR>\n" );
document.write( "1.28=(1+r)^4<BR>\n" );
document.write( "ln 1.28=4 ln (1+r)<BR>\n" );
document.write( "ln(1+r)=0.0617, don't round<BR>\n" );
document.write( "raise everything to the e power<BR>\n" );
document.write( "1+r=e^0.0617=1.064<BR>\n" );
document.write( "r=0.064 or 6.4% </SPAN>\n" );
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