College

If [tex]f(3)=191.5[/tex] when [tex]r=0.03[/tex] for the function [tex]f(t)=P e^{rt}[/tex], then what is the approximate value of [tex]P[/tex]?

A. 210
B. 175
C. 471
D. 78

Answer :

To solve the problem, we need to find the value of [tex]\( P \)[/tex] for the function [tex]\( f(t) = P e^{rt} \)[/tex] given that [tex]\( f(3) = 191.5 \)[/tex] when [tex]\( r = 0.03 \)[/tex].

Let's break it down step-by-step:

1. Understand the Function:
The function is given as [tex]\( f(t) = P e^{rt} \)[/tex]. We know that when [tex]\( t = 3 \)[/tex], the function value is [tex]\( f(3) = 191.5 \)[/tex].

2. Substitute and Set Up the Equation:
Substitute the known values into the equation:
[tex]\[
191.5 = P \cdot e^{0.03 \times 3}
\][/tex]
This means:
[tex]\[
191.5 = P \cdot e^{0.09}
\][/tex]

3. Calculate [tex]\( e^{0.09} \)[/tex]:
Approximate the value of the exponential function:
[tex]\[
e^{0.09} \approx 1.0941742837052104
\][/tex]

4. Solve for [tex]\( P \)[/tex]:
Rearrange the equation to solve for [tex]\( P \)[/tex]:
[tex]\[
P = \frac{191.5}{1.0941742837052104}
\][/tex]
[tex]\[
P \approx 175.01782197944019
\][/tex]

5. Choose the Closest Approximate Value:
The approximate value of [tex]\( P \)[/tex] is about 175.02, which is closest to option B: 175.

Therefore, the correct answer is B. 175.