Question 701494: If the population is decreasing at 2.3% per year and the population is currently 125,000. What is the exponentional model? What will the population be in 15 years? How long will it take to reach 25,000.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! If the population is decreasing at 2.3% per year and the population is currently 125,000. What is the exponentional model? What will the population be in 15 years? How long will it take to reach 25,000.
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Each year 97.7% of last year's population survives.
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A(t) = 125000(0.977)^t
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Solve 125000(0.977)^t = 25000
0.977^t = 1/5
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Take the log and solve for "t":
t = log(1/5)/log(0.977)
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t = 69 years
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Cheers,
Stan H.
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