document.write( "Question 1193432: MAT 145: Topics In Contemporary Math\r
\n" ); document.write( "\n" ); document.write( " 20: Logistic Growth\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "1) The population of fuzzy quadrupeds increases by 50%) every month after they are
\n" ); document.write( "introduced to a new region. Suppose 30 fuzzy quadrupeds are accidentally introduced to
\n" ); document.write( "Springfield when a family visited the region to which fuzzy quadrupeds are native.
\n" ); document.write( "However, Springfield only has a carrying capacity of 70 fuzzy quadrupeds. How many
\n" ); document.write( "fuzzy quadrupeds would there be for each of the first five months after they were
\n" ); document.write( "introduced to the new region?
\n" ); document.write( "Month Formula Population size
\n" ); document.write( "0 Beginning population
\n" ); document.write( "1
\n" ); document.write( "2
\n" ); document.write( "3
\n" ); document.write( "4
\n" ); document.write( "5
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #825613 by greenestamps(13200)\"\" \"About 
You can put this solution on YOUR website!


\n" ); document.write( "-----------------------------------------------------------------

\n" ); document.write( "(Answered the other day for (perhaps) a different student...)

\n" ); document.write( "Solution copied here.

\n" ); document.write( "-----------------------------------------------------------------

\n" ); document.write( "Here is a logistic growth formula:

\n" ); document.write( "\"f%28x%29=L%2F%281%2Ba%2Ae%5E%28-bt%29%29\"

\n" ); document.write( "L is the carrying capacity, given as 70.

\n" ); document.write( "a and b are constants to be determined from the given information.

\n" ); document.write( "The initial population, f(0), is 30:

\n" ); document.write( "\"f%280%29=70%2F%281%2Ba%2Ae%5E0%29=70%2F%281%2Ba%29=30\"
\n" ); document.write( "\"70=30%281%2Ba%29=30%2B30a\"
\n" ); document.write( "\"40=30a\"
\n" ); document.write( "\"a=40%2F30=4%2F3\"

\n" ); document.write( "The population increases by 50% each month, so the population after one month is 1.5(30)=45:

\n" ); document.write( "\"45=70%2F%281%2B%284%2F3%29e%5E%28%28-b%281%29%29%29%29\"
\n" ); document.write( "\"70=45%281%2B%284%2F3%29e%5E%28-b%29%29\"
\n" ); document.write( "\"70=45%2B60e%5E%28-b%29\"
\n" ); document.write( "\"25=60e%5E%28-b%29\"
\n" ); document.write( "\"e%5E%28-b%29=25%2F60=5%2F12\"
\n" ); document.write( "\"-b=ln%285%2F12%29\" =-0.87547 to 5 decimal places
\n" ); document.write( "\"b=0.87547\"

\n" ); document.write( "\"f%28n%29=70%2F%281%2B%284%2F3%29e%5E%28%28-0.87547%29n%29%29\"

\n" ); document.write( "That function gives the following populations after n months to fill your chart:
\r\n" );
document.write( "  months   population  (rounded)\r\n" );
document.write( " -------------------------------\r\n" );
document.write( "    0      30             30\r\n" );
document.write( "    1      45             45\r\n" );
document.write( "    2      56.842         57\r\n" );
document.write( "    3      63.842         64\r\n" );
document.write( "    4      67.296         67\r\n" );
document.write( "    5      68.847         69\r\n" );
document.write( "    .\r\n" );
document.write( "    .\r\n" );
document.write( "    .\r\n" );
document.write( "   10      69.985         70
\n" ); document.write( "
\n" );