Question 80577: In 1984, the population of the world was about 4.8 billion and the yearly growth rate was 2%. The equation giving the population P in terms of the time t (in years) is P = 4.8e0.02t. Estimate the population in 2007. (If 1984 is t = 0, then 2007 is t = 23.) When will the population be 10 billion? How many years will it take for the population to double?
Answer: The population in 2007 will be billion. The populaton will be 10 billion in the year . (Round the year off.) It will take years for the population to double. (Round up to the nearest whole number for years.)
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! In 1984, the population of the world was about 4.8 billion and the yearly growth rate was 2%. The equation giving the population P in terms of the time t (in years) is P = 4.8e0.02t. Estimate the population in 2007. (If 1984 is t = 0, then 2007 is t = 23.) When will the population be 10 billion? How many years will it take for the population to double?
Answer: The population in 2007 will be billion. The populaton will be 10 billion in the year . (Round the year off.) It will take years for the population to double. (Round up to the nearest whole number for years.)
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Your equation is wrong.
The equation is P(t)=4.8(1.02)^t where t is the # of years after 1984.
If the growth rate is 2% the population
after 23 years is P(23)=4.8(1.02)^23=7.57 billion
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When will it reach 10 billion?
10 = 4.8(1.02)^t
2.0833333.. = 1.02^t
t= [ln2.08333...]/ln(1.02]
t=37.06 years
or 1984 +37 = 2021
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When will it double; ie when will it be 9.6 billion
9.6=4.8(1.02)^t
2=(1.02)^t
t=ln2 / ln1.02 = 35 years
1984=35 = 2019
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Cheers,
Stan H.
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