document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1116381>Question 1116381</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A town has a population of 3500 people at time t = 0. In each case, write an<BR>\n" );
document.write( "equation for the population P, of the town as a function of year t.<BR>\n" );
document.write( "a) the population size increases by 80 per year. <BR>\n" );
document.write( "I believe this answer to be P=3500 +80t<BR>\n" );
document.write( "b)The population size increases by 3.2 percent per year.<BR>\n" );
document.write( "I believe this answer to be P=3500(1.032)^t<BR>\n" );
document.write( "c) The population increases continuously at a rate of 2.65% per year.<BR>\n" );
document.write( "I believe this answer to be P=3500e^0.0265t<BR>\n" );
document.write( "d) Find the doubling time for each of the functions you found above: <BR>\n" );
document.write( "I believe a is 30.6 years, b is 67.8 years, but I do not know how to find the doubling time of d. <BR>\n" );
document.write( "Please help! 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 #731263 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=731263\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a is correct<BR>\n" );
document.write( "b is also correct<BR>\n" );
document.write( "c is correct<BR>\n" );
document.write( "for d, with continuous<BR>\n" );
document.write( "7000=3500e^(0.0265t)<BR>\n" );
document.write( "2=e^(0.0265t)<BR>\n" );
document.write( "ln2=0.0265t<BR>\n" );
document.write( "0.693=0.0265t<BR>\n" );
document.write( "t=26.25 years<BR>\n" );
document.write( "-------<BR>\n" );
document.write( "for d, with 3.2 per cent<BR>\n" );
document.write( "2=1.032^t<BR>\n" );
document.write( "ln both sides<BR>\n" );
document.write( "ln 2=t ln (1.032)<BR>\n" );
document.write( "divide both sides by ln (1.032)<BR>\n" );
document.write( "t=22.0 years<BR>\n" );
document.write( "------<BR>\n" );
document.write( "for d, with an increase of 80 per year<BR>\n" );
document.write( "doubles after 3500/80=43.75 years </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );