College

If [tex]$f(4)=246.4$[/tex] when [tex]$r=0.04$[/tex] for the function [tex]$f(t)=P e^{rt}$[/tex], then what is the approximate value of [tex]$P$[/tex]?

A. [tex]50^{\circ}[/tex]
B. 210
C. 1220
D. 289

Answer :

To find the approximate value of [tex]\( P \)[/tex] for the function [tex]\( f(t) = P \cdot e^{rt} \)[/tex] when [tex]\( f(4) = 246.4 \)[/tex] and [tex]\( r = 0.04 \)[/tex], follow these steps:

1. Write Down the Given Equation:

You have the equation [tex]\( f(t) = P \cdot e^{rt} \)[/tex].

2. Substitute the Given Values:

Substitute [tex]\( t = 4 \)[/tex], [tex]\( f(4) = 246.4 \)[/tex], and [tex]\( r = 0.04 \)[/tex] into the equation:

[tex]\[
246.4 = P \cdot e^{0.04 \cdot 4}
\][/tex]

3. Simplify the Exponential Term:

Calculate the exponent: [tex]\( 0.04 \cdot 4 = 0.16 \)[/tex], so the equation becomes:

[tex]\[
246.4 = P \cdot e^{0.16}
\][/tex]

4. Solve for [tex]\( P \)[/tex]:

Divide both sides of the equation by [tex]\( e^{0.16} \)[/tex] to solve for [tex]\( P \)[/tex]:

[tex]\[
P = \frac{246.4}{e^{0.16}}
\][/tex]

When you compute this division, you find that:

[tex]\[
P \approx 209.97
\][/tex]

5. Select the Closest Option:

The closest option to [tex]\( 209.97 \)[/tex] from the choices provided is [tex]\( 210 \)[/tex].

Therefore, the approximate value of [tex]\( P \)[/tex] is:

B. 210