SOLUTION: A country's population in 1992 was 72 million. In 1998 it was 76 million. Estimate the population in 2012 using the exponential growth formula. Round your answer to the nearest mil

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Question 1023073: A country's population in 1992 was 72 million. In 1998 it was 76 million. Estimate the population in 2012 using the exponential growth formula. Round your answer to the nearest million.
P=Ae^kt
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
You want to show it in pure text as P=Ae^(kt) and when rendered, P=Ae%5E%28kt%29.

Let t be number of years after 1992. This means that 1998 uses t=6. Also, year 2012 is t=10. A=72 for 72 million people at t=0.

76=72%2Ae%5E%28k%2A6%29
ln%2876%29=ln%2872%2Ae%5E%28k%2A6%29%29
ln%2876%29=ln%2872%29%2B6k%2Aln%28e%29
6k%2A1%2Bln%2872%29=ln%2876%29
6k=ln%2876%29-ln%2872%29
k=%28ln%2876%29-ln%2872%29%29%2F6--------compute this for the value of k.


Now your model is P=72%2Ae%5E%280.009011%2At%29; just let t=10 and evaluate P.