College

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

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

Answer :

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

1. Understand the problem: We are given a function [tex]\( f(t) = P e^{rt} \)[/tex]. We know that [tex]\( f(5) = 288.9 \)[/tex] and [tex]\( r = 0.05 \)[/tex], and we need to find the value of [tex]\( P \)[/tex].

2. Set up the equation:
[tex]\[
f(5) = P e^{0.05 \times 5}
\][/tex]
This simplifies to:
[tex]\[
288.9 = P e^{0.25}
\][/tex]

3. Solve for [tex]\( P \)[/tex]:
We need to isolate [tex]\( P \)[/tex] in the equation:
[tex]\[
P = \frac{288.9}{e^{0.25}}
\][/tex]

4. Calculate [tex]\( e^{0.25} \)[/tex]: The value of [tex]\( e^{0.25} \)[/tex] is approximately [tex]\( 1.284 \)[/tex].

5. Calculate [tex]\( P \)[/tex]:
Divide 288.9 by 1.284 to find [tex]\( P \)[/tex]:
[tex]\[
P \approx \frac{288.9}{1.284} \approx 225
\][/tex]

This calculation leads us to conclude that the approximate value of [tex]\( P \)[/tex] is 225, which corresponds to option C.