document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=662331>Question 662331</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the time required for an investment of 5000 dollars to grow to 7200 dollars at an interest rate of 7.5 percent per year, compounded quarterly. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #412158 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=412158\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find the time required for an investment of 5000 dollars to grow to 7200 dollars at an interest rate of 7.5 percent per year, compounded quarterly.<BR>\n" );
document.write( "**<BR>\n" );
document.write( "compound interest formula: A=P(1+r)^n, P=initial investment, r=interest rate/period, n=number of periods, A=amt after n-periods.<BR>\n" );
document.write( "For given problem:<BR>\n" );
document.write( "P=5000<BR>\n" );
document.write( "r=.075/4=.01875<BR>\n" );
document.write( "n=to find<BR>\n" );
document.write( "A=7200<BR>\n" );
document.write( "..<BR>\n" );
document.write( "7200=5000(1+.01875)^n<BR>\n" );
document.write( "7200/5000=(1.0175)^n<BR>\n" );
document.write( "1.44=(1.0175)^n<BR>\n" );
document.write( "take log of both sides<BR>\n" );
document.write( "log(1.44)=n*log(1.0175)<BR>\n" );
document.write( "n=log1.44/log(1.0175)<BR>\n" );
document.write( "n&#8776;21 quarters or 5.25 years     </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );