A bacteria culture starts with 300 bacteria and grows at a rate proportional to its size. After 3 hours, there are 9000 bacteria(adsbygoogle = window.adsbygoogle || []).push({});

A.) Find an expression for the number of bacteria after t hours. for this part, i got [tex]300*e^{1.133732*t}[/tex]

B.) Find the number of bacteria after 4 hours. well using the expression from above and subbing in 4, i get 27965.04104

C.) Find the growth rate after 4 hours. this just means that i need to solve for k right?

p(t) = 300e^{kt}

p(3) = 300e^{3k} = 9000

solved for k and got 1.133% right?

D.) After how many hours will the population reach 30000

well setting the equation from part A equal to 30000 and solved for t and got 4.319991

i know that at least one of these are wrong, but i cant figure out which one. can someone tell me what im doing wrong?

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# Homework Help: Population growth

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