Question 1029620
In 1990, the population of Africa was 643 million and by 2000 it had grown to 813 million.
Points:: (0,643); (10,813)
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a. Use the exponential growth model A=Aoe^kt, in which t the number of years
after 1990, to find the exponential growth function that models the data.
813 = 643*e^(k*10)
e^(10k) = 1.2644
10k = ln(1.2644)
k = 0.02346
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Eq:: A(t) = 643*e^(0.02346t)

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b. By which year will Africa's population reach two billion?
Note:: 2 billion = 2000 million
2000 = 643*e^(0.02346t)
e^0.02346t = 3.11
0.02346t = ln(3.11) = 1.1346
t = 48.36 years
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Ans: 1990 + 48.36 years occurs in the year 2039
Cheers,
Stan H.
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