College

If [tex]f(5) = 288.9[/tex] when [tex]r = 0.05[/tex] for the function [tex]f(t) = P e^{rt}[/tex], then what is the approximate value of [tex]P[/tex]?

A. 225
B. 24
C. 371
D. 3520

Answer :

To find the approximate value of [tex]\( P \)[/tex] for the function [tex]\( f(t) = P e^{rt} \)[/tex], with the given information that [tex]\( f(5) = 288.9 \)[/tex] and [tex]\( r = 0.05 \)[/tex], follow these steps:

1. Substitute the Known Values:
Plug the values into the equation. We have [tex]\( f(5) = 288.9 \)[/tex], [tex]\( t = 5 \)[/tex], and [tex]\( r = 0.05 \)[/tex]. The equation becomes:
[tex]\[
288.9 = P \times e^{0.05 \times 5}
\][/tex]

2. Calculate the Exponent:
First, calculate the exponent [tex]\( 0.05 \times 5 \)[/tex], which equals [tex]\( 0.25 \)[/tex]. So the equation is:
[tex]\[
288.9 = P \times e^{0.25}
\][/tex]

3. Solve for [tex]\( P \)[/tex]:
To find [tex]\( P \)[/tex], we need to divide both sides of the equation by [tex]\( e^{0.25} \)[/tex]:
[tex]\[
P = \frac{288.9}{e^{0.25}}
\][/tex]

4. Approximate [tex]\( e^{0.25} \)[/tex]:
Using a calculator, approximate [tex]\( e^{0.25} \)[/tex].

5. Calculate [tex]\( P \)[/tex]:
Divide 288.9 by the approximate value of [tex]\( e^{0.25} \)[/tex].

The result for [tex]\( P \)[/tex] is approximately 225.

Therefore, the correct choice is:
A. 225