document.write( "Question 741827: Is there a formula to solve this question....The population of a community was 82,000 at the beginning of 2000. Assuming a rate of growth of 1.6% per year since 2000, what will be the population be at the beginning of 2025?
\n" ); document.write( "I can manually get the answer but would rather use a formula. Is there one that will work? I can't seem to get the formulas that I know to work.
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Algebra.Com's Answer #452167 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
\"t\"= years since the beginning of 2000
\n" ); document.write( "At the beginning of 2000, \"t=0\" and the population is
\n" ); document.write( "\"P%280%29=P%5B0%5D=82000\"
\n" ); document.write( "At the beginning of 2001, 1 year has passed and the population has increased by 1.6%,
\n" ); document.write( "meaning that the increase is \"1.6%2F100=0.016\" of the initial amount,
\n" ); document.write( "so it has increased by \"0.016%2AP%5B0%5D=0.016%2A82000\"
\n" ); document.write( "That means that at the beginning of 2001, when \"t=1\", the population is
\n" ); document.write( "\"P%5B0%5D%2B0.016P%5B0%5D=P%5B0%5D%2A%281%2B0.016%29=P%5B0%5D%2A1.016\"
\n" ); document.write( "With numbers it would be \"82000%2A1.016=83312\"
\n" ); document.write( "That number is not important. What's important is that the population number got multiplied times \"1.016=1%2B0.016\".
\n" ); document.write( "With the passage of each year the population gets increased (multiplied) by a factor of \"1.016\".
\n" ); document.write( "After 2 years, it would have been multiplied by 1.016 again, and it would be \"%28P%5B0%5D%2A1.016%29%2A1.016=P%5B0%5D%2A1.016%5E2\".
\n" ); document.write( "After 3 years, it would have been multiplied by 1.016 again, and it would be \"%28P%5B0%5D%2A1.016%5E2%29%2A1.016=P%5B0%5D%2A1.016%5E3\", and so on.
\n" ); document.write( "If you are studying sequences and series, your teacher would say that it is a geometric sequence with a common ratio of \"1.016\".
\n" ); document.write( "After \"t\" years the population will be \"P%28t%29=P%5B0%5D%2A1.016%5Et\".
\n" ); document.write( "Using your initial population of \"82000\" at the beginning of 2000, it is
\n" ); document.write( "\"highlight%28P%28t%29=82000%2A1.016%5Et%29\"
\n" ); document.write( "At the beginning of 2025, \"t=25\" and my calculator says that
\n" ); document.write( "\"P%2825%29=82000%2A1.016%5E25=highlight%28121943%29\" (rounded)
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\n" ); document.write( "NOTE: That kind of growth is called exponential growth.
\n" ); document.write( "If you use the growth factor per unit of time in the formula, the time will be the exponent.
\n" ); document.write( "In mathematics they like to use powers of the irrational number \"e\" instead, so you see formulas like
\n" ); document.write( "\"P%28t%29=P%5B0%5D%2Ae%5Ekt\", but if you do not know about \"e\" and natural logarithms, don't worry about it, because I do not think that \"e\" would help your calculation at all.
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