document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=277107>Question 277107</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If I have 10,000 dollars to invest at 8% compounded quarterly, how long will it take to earn $5,000 in interest.  Please can you provide a formula for this problem. \r<BR>\n" );
document.write( "\n" );
document.write( "Thank you  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #201809 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=201809\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the formula is ___ A = P (1 + r)^n<BR>\n" );
document.write( "___ A = current Amount<BR>\n" );
document.write( "___ P = starting Principal<BR>\n" );
document.write( "___ r = interest rate per compounding period<BR>\n" );
document.write( "___ n = number of compounding periods\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "in this case ___ 15000 = 10000 (1 + .02)^(t/4) (where t is in years)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "dividing by 10000 ___ 1.5 = (1.02)^(t/4)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "taking logarithm ___ log(1.5) = (t/4) log(1.02)\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "dividing by log(1.02) ___ [log(1.5)] / [log(1.02)] = t / 4\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "multiplying by 4 ___ 4 {[log(1.5)] / [log(1.02)]} = t </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );