A country's population in 1992 was 28 million.
In 1999 it was 30 million. Estimate
the population in 2008 using the exponential
growth formula. Round your answer to the
nearest million.
P = Ae^kt
Enter the correct answer

Respuesta :

Answer:

The Estimate for the population in 2008 is 33 million

Step-by-step explanation:

Exponential Function

Some real-life situations can be modeled by using the exponential function which takes the form

[tex]P = Ae^{kt}[/tex]

Where A and k are constants, and t is the independent variable.

We are given two data. A country's population in 1992 was 28 million and in 1999 it was 30 million.

Let's express P as the population in million and t the time in years elapsed since 1992.

The information can be written as two points: (0,28), (7,30). Please recall that the second data comes from the year 1999, seven years after the zero reference.

We only have to replace both points in the general form:

[tex]28 = Ae^{k(0)}=A(1)=A[/tex]

We know A=28 million

Also

[tex]30 = 28e^{k{(7)}}[/tex]

[tex]28e^{7k}=30[/tex]

[tex]\displaystyle e^{7k}=\frac{30}{28}[/tex]

Taking logarithms

[tex]\displaystyle 7k=ln\left ( \frac{30}{28} \right )[/tex]

Solving for k

[tex]\displaystyle k=\frac{ln\left ( \frac{30}{28} \right )}{7}[/tex]

[tex]k=0.00986[/tex]

The model is complete now:

[tex]P = 28e^{0.00986t}[/tex]

For the year 2008, t=2008-1992=16 years

[tex]P = 28e^{0.00986(16)}[/tex]

[tex]P = 28(1.1708)[/tex]

[tex]P=32.78\ \approx 33[/tex]

The Estimate for the population in 2008 is 33 million