How Is Doubling Time Calculated in Population Growth Models?

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Homework Help Overview

The discussion revolves around calculating the doubling time in population growth models, specifically using an exponential growth formula. The original poster presents a formula for population growth and seeks guidance on how to determine the doubling time without using a calculator.

Discussion Character

  • Exploratory, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss substituting values into the population equation and taking the natural logarithm of both sides to simplify the problem. There is also mention of using different initial values to demonstrate consistency in the doubling time calculation.

Discussion Status

Some participants have provided suggestions on how to approach the problem, including plugging in known values and simplifying the equation. The discussion is ongoing, with participants exploring different methods and interpretations without reaching a consensus.

Contextual Notes

The original poster has been instructed to leave the answer in terms of natural logarithms and not to use a calculator, which may limit the approaches discussed.

Christo
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1. The population of a certain country grows according to the formula:

N = N0e^kt

Where N is the number of people (in millions) after t years, N0 is the initial number of people (in millions) and k = 1/20 ln 5/4.

Calculate the doubling time of this population. Leave your answer in terms
of ln : Do not use a calculator.
2. I don't understand where to start off.3. I have basically come to the conclusion that N = 2N0
That is how far I have come. I know I haven't done anything as of yet. But any help would be appreciated
 
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Well, you were given a value for k. Did you plug this value into the population equation and make any obvious simplifications?
 
Use N=2 and No=1.
Take natural log of both sides of the equation.
 
Thanks for the info, will plug in the variables and see where I end up.
 
To see that you get the same "doubling time" for any initial value, take N= 2N_0.
 

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