High School

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

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

Answer :

To find the approximate value of [tex]\( P \)[/tex] for the function [tex]\( f(t) = P e^{r t} \)[/tex], given that [tex]\( f(3) = 191.5 \)[/tex] and [tex]\( r = 0.03 \)[/tex], follow these steps:

1. Substitute the Known Values:

We know:
[tex]\[
f(t) = P e^{r t}
\][/tex]

Given:
[tex]\( f(3) = 191.5 \)[/tex]
[tex]\( r = 0.03 \)[/tex]
[tex]\( t = 3 \)[/tex]

Substitute these into the function:
[tex]\[
191.5 = P \times e^{0.03 \times 3}
\][/tex]

2. Calculate the Exponential Term:

First, calculate the exponent:
[tex]\[
0.03 \times 3 = 0.09
\][/tex]

Then, calculate the value of [tex]\( e^{0.09} \)[/tex].

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

Rearrange the equation to solve for [tex]\( P \)[/tex]:
[tex]\[
P = \frac{191.5}{e^{0.09}}
\][/tex]

4. Approximate [tex]\( P \)[/tex]:

After calculating the above expression, you find that the approximate value of [tex]\( P \)[/tex] is 175.

Therefore, the approximate value of [tex]\( P \)[/tex] is [tex]\( \boxed{175} \)[/tex], which corresponds to option B.