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The population of a town has grown at an annual rate of approximately 2.7%. How long will it take for its population of 18 450 people to double at this growth rate?

 Apr 18, 2017
 #1
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So basically, all you have to do is set the doubled population equal to the original times the rate of change to the x-1nth power.

 Apr 18, 2017
 #2
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The beginning population is irrelevant...we have

 

2  = (1 + .027)^t    where t is the time to double

 

Take the log  of both sides

 

log 2   =  log ( 1 + .027)^t     and we can write

 

log 2  = t * log (1 + .027)     divide both sides by log (1 + .027)

 

log (2) / log (1 + .027)  = t  ≈   26 years 

 

 

cool cool cool

 Apr 18, 2017
edited by CPhill  Apr 18, 2017

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