document.write( "Question 79656: Please help me with this problem.I am having a lot of issues with these types of problems.I tried plugging in 200 for P and 3 for t but I still cant get it right.\r
\n" ); document.write( "\n" ); document.write( "The population P of a certain culture is expected to be given by a model P=100e^rt where r is a constant to be determined and t is the number of days since the original population is expected to reach 200 in 3 days.
\n" ); document.write( "a. 0.231
\n" ); document.write( "b. 0.549
\n" ); document.write( "c. 1.098
\n" ); document.write( "d. 1.50
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Algebra.Com's Answer #57163 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
The population P of a certain culture is expected to be given by a model P=100e^rt where r is a constant to be determined and t is the number of days since the original population is expected to reach 200 in 3 days.
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\n" ); document.write( "100(e^rt) = P
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\n" ); document.write( "Substitute for t and P
\n" ); document.write( "100(e^(3r)) = 200
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\n" ); document.write( "Divide both sides by 100 and you have:
\n" ); document.write( "e^(3r) = 2
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\n" ); document.write( "Find nat log of both sides:
\n" ); document.write( "ln(e^3r) = ln(2)
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\n" ); document.write( "3r*ln(e) = ln(2); log equiv of exponents
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\n" ); document.write( "3r = .693147; remember ln(e) = 1
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\n" ); document.write( "r = .693147/3
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\n" ); document.write( "r = .231
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\n" ); document.write( "Check solution with a good calc: enter 100(e^(.231*3)) = 199.97 ~ 200
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