Questions: d the value of r, where r represents and interest rate in decimal form. Give your answer as a percent, rounded to arest hundredth. SHOW ALL WORK!
24) 90,000=600(1+r)^120
r=
%
Transcript text: $d$ the value of $r$, where $r$ represents and interest rate in decimal form. Give your answer as a percent, rounded to arest hundredth. SHOW ALL WORK!
24) $90,000=600(1+\mathrm{r})^{120}$
\[
\mathrm{r}=
\]
\%
Solution
Solution Steps
To solve for \( r \) in the equation \( 90,000 = 600(1 + r)^{120} \), we need to isolate \( r \). This involves the following steps:
Divide both sides of the equation by 600.
Take the 120th root of both sides to eliminate the exponent.
Subtract 1 from both sides to solve for \( r \).
Convert \( r \) from decimal form to a percentage and round to the nearest hundredth.
Step 1: Set Up the Equation
We start with the equation given in the problem:
\[
90,000 = 600(1 + r)^{120}
\]
Step 2: Isolate the Exponential Term
Divide both sides by 600 to isolate the term containing \( r \):
\[
\frac{90,000}{600} = (1 + r)^{120}
\]
This simplifies to:
\[
150 = (1 + r)^{120}
\]
Step 3: Take the 120th Root
To solve for \( 1 + r \), take the 120th root of both sides:
\[
1 + r = 150^{\frac{1}{120}}
\]
Step 4: Solve for \( r \)
Subtract 1 from both sides to find \( r \):
\[
r = 150^{\frac{1}{120}} - 1
\]
Step 5: Convert to Percentage
Convert \( r \) from decimal form to a percentage:
\[
r \approx 0.04263930755917267
\]
Thus,
\[
r \times 100 \approx 4.263930755917267
\]
Rounding to the nearest hundredth gives:
\[
r \approx 4.26\%
\]