The rat population in a major metropolitan city is given by the formula [tex]n(t)=82 e^{0.015 t}[/tex] where [tex]t[/tex] is measured in years since 2001 and [tex]n(t)[/tex] is measured in millions.

1. What was the rat population in 2001? [tex]\(\square\)[/tex] rats

2. What does the model predict the rat population was in the year 2019? [tex]\(\square\)[/tex] rats



Answer :

To answer the questions about the rat population in a major metropolitan city, we will use the given formula [tex]\( n(t) = 82 e^{0.015 t} \)[/tex], where [tex]\( t \)[/tex] is measured in years since 2001, and [tex]\( n(t) \)[/tex] is measured in millions.

### Part 1: Rat Population in 2001
To find the rat population in 2001, we need to evaluate the formula at [tex]\( t = 0 \)[/tex] (since [tex]\( t \)[/tex] represents the number of years since 2001).

[tex]\[ n(0) = 82 e^{0.015 \cdot 0} \][/tex]

Since [tex]\( 0.015 \cdot 0 = 0 \)[/tex], the equation simplifies to:

[tex]\[ n(0) = 82 e^0 \][/tex]

We know that [tex]\( e^0 = 1 \)[/tex], thus:

[tex]\[ n(0) = 82 \times 1 = 82 \][/tex]

So, the rat population in 2001 was:
[tex]\[ 82 \text{ million rats} \][/tex]

### Part 2: Rat Population in 2019
To find the predicted rat population in 2019, we need to evaluate the formula at [tex]\( t = 2019 - 2001 = 18 \)[/tex].

[tex]\[ n(18) = 82 e^{0.015 \cdot 18} \][/tex]

Calculating the exponent:
[tex]\[ 0.015 \cdot 18 = 0.27 \][/tex]

So, the equation becomes:

[tex]\[ n(18) = 82 e^{0.27} \][/tex]

From the result given, we know that the exponential calculation and multiplication result in:

[tex]\[ n(18) = 107.41708496012627 \][/tex]

So, the model predicts that the rat population in 2019 was:
[tex]\[ 107.42 \text{ million rats} \text{ (rounded to two decimal places)} \][/tex]

Therefore, the solutions to the questions are:

1. The rat population in 2001 was [tex]\( 82 \)[/tex] million rats.
2. The model predicts that the rat population in 2019 was approximately [tex]\( 107.42 \)[/tex] million rats.