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The exponential model A = 178e^0007t describes the population, A, of a country in millions, t years after 2003. Use the model to determine when the population of the country will be 190 million.(Round to the nearest year as needed.)

User Jonny Phelps
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1 Answer

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16 votes

To determine how many years has passed we equate the population we need in the function and then we solve for t:


\begin{gathered} 190=178e^(0.007t) \\ e^(0.007t)=(190)/(178) \\ \ln e^(0.007t)=\ln ((190)/(178)) \\ 0.007t=\ln ((190)/(178)) \\ t=(1)/(0.007)\ln ((190)/(178)) \\ t=9.32 \end{gathered}

This means that in nine years (approximately) the population will be 190 millions, therefore the population will be that amount in 2012.

User Ariefs
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