Hi, I dont know what I am doing wrong in this problem:(adsbygoogle = window.adsbygoogle || []).push({});

In 1980 the world population was approximately 4.5 billion and in the year 2000 it was approximately 6 billion. Assume that the world population at each time t increases at a rate proprtional to the population at time t. Measure t in year after 1980.

Find the growth constant and give the world population at any time t.

What I did is I set the year 1980 as reference.A(t=0)= A_{o}=4.5

A(20)=6.

we know that A(t)=A_{o}*e^{r*t}. (r =rate)

so I get 6=A(t)=4.5*e^{r*20}.

then I solve for r. I found r=.014.

The solution the teacher not isr=.0231

Can someone please tell me what I missed?

Thank you

B

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# Homework Help: Populatiopn growth

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