Hi,

I know how to find the population growth if a growth rate is given but how do I find thegrowth rateif only number of years and estimated population given.ie population now = 23600 and after 53 years will exceed 35000

Thanks...Mark

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- Jan 25th 2010, 02:26 AMmanich44Population Growth rate formula
Hi,

I know how to find the population growth if a growth rate is given but how do I find the__growth rate__if only number of years and estimated population given.ie population now = 23600 and after 53 years will exceed 35000

Thanks...Mark - Jan 25th 2010, 02:42 AMe^(i*pi)
Exponential growth is modelled by $\displaystyle A(t) = A_0e^{kt}$

Where

- $\displaystyle A(t)$ = Number at time $\displaystyle t$
- $\displaystyle A_0$ = Number at $\displaystyle t=0$
- $\displaystyle k$ = growth constant $\displaystyle k>0$
- $\displaystyle t$ = time

In your example there is enough information to find $\displaystyle k$. Rearranging the equation to make k the subject:

$\displaystyle k = \frac{1}{t}(ln[A(t)] - ln(A_0))$

The equation at the top is one you should learn as it's rarely given in exams