document.write( "Question 682835: I have a problem I can not figure out. In 1975, Visalia had a population of 65,000. In 2000 the population was 99,500. Assuming exponential growth, estimate the population in the 2015. Use A=A0e^kt \n" ); document.write( "
Algebra.Com's Answer #423371 by KMST(5328)\"\" \"About 
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\"A=A%5B0%5De%5Ekt\"
\n" ); document.write( "For \"t=0\", \"A=A%5B0%5De%5E%28k%2A0%29\" --> \"A=A%5B0%5De%5E0\" --> \"A=A%5B0%5D%2A1\" --> \"A=A%5B0%5D\"
\n" ); document.write( "\"A%5B0%5D\" is the population at whatever time we decide to take as \"t=o\".
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\n" ); document.write( "Taking 1975 as time zero, \"t=year-1975\", is a good choice.
\n" ); document.write( "In 1975, \"t=1975-1975=0\",
\n" ); document.write( "Visalia had a population of 65,000, \"A=A%5B0%5D=65000\"
\n" ); document.write( "Now we can write the exponential function as
\n" ); document.write( "\"highlight%28A=65000e%5Ekt%29\",
\n" ); document.write( "but we still have to find \"k\".
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\n" ); document.write( "In 2000, \"t=2000-1975=25\",
\n" ); document.write( "and the population was 99,500,
\n" ); document.write( "so \"A=65000e%5E25k=99500\" --> \"e%5E25k=99500%2F65000\" --> \"25k=ln%2899500%2F65000%29\" --> \"k=%281%2F25%29ln%2899500%2F65000%29\" --> \"highlight%28k=0.0170308%29\" (rounded approximation)
\n" ); document.write( "Now we can write the exponential function as
\n" ); document.write( "\"highlight%28A=65000e%5E%280.0170308t%29%29\".
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\n" ); document.write( "In the year 2015, \"t=2015-1975=40\", and we estimate
\n" ); document.write( "\"A=65000e%5E%280.0170308%2A40%29\" --> \"A=65000e%5E0.681232\" --> \"A=65000%2A1.976311\" --> \"highlight%28A=128460%29\".
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