document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=600561>Question 600561</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Solve the problem. Use the formula N = Iekt, where N is the population at time t, I is the initial population, and k is a growth constant equal to the percent of growth (expressed in decimal form) per unit of time. How long will it take for the population of a certain country to double if its annual growth rate is 7.7%? Round your answer to the nearest year. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #379379 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=379379\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> First off, let's use the fact that the population is growing at an annual rate of 7.7% to find the value of k.\r<BR>\n" );
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document.write( "If the initial population is say 1000 people, then in one year, we add 7.7% of that 1000 to the initial population to get: 1000 + 0.077*1000 = 1000 + 77 = 1077\r<BR>\n" );
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document.write( "So I = 1000 and N = 1077. This all happens in one year, so t = 1. Use these three variables to find k\r<BR>\n" );
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document.write( "Now that you know the value of k, use it to find the value of t when I = 1000, N = 2000 (double the population of the initial 1000)\r<BR>\n" );
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document.write( "So it will take roughly 9.3442 years for the population to double. </SPAN>\n" );
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