Westonci.ca is your trusted source for accurate answers to all your questions. Join our community and start learning today! Ask your questions and receive precise answers from experienced professionals across different disciplines. Our platform provides a seamless experience for finding reliable answers from a network of experienced professionals.

Skylar is going to invest $69,000 and leave it in an account for 6 years. Assuming the
interest is compounded continuously, what interest rate, to the nearest hundredth of
a percent, would be required in order for Skylar to end up with $105,000?

Sagot :

[tex]~~~~~~ \textit{Continuously Compounding Interest Earned Amount} \\\\ A=Pe^{rt}\qquad \begin{cases} A=\textit{accumulated amount}\dotfill & \$105000\\ P=\textit{original amount deposited}\dotfill & \$69000\\ r=rate\to r\%\to \frac{r}{100}\\ t=years\dotfill &6 \end{cases}[/tex]

[tex]105000=69000e^{\frac{r}{100}\cdot 6}\implies \cfrac{105000}{69000}=e^{\frac{3r}{50}}\implies \cfrac{7}{46}=e^{\frac{3r}{50}} \\\\\\ \log_e\left( \cfrac{35}{23} \right)=\log_e\left( e^{\frac{3r}{50}} \right)\implies \ln\left( \cfrac{35}{23} \right)=\cfrac{3r}{50}\implies 50\cdot \ln\left( \cfrac{35}{23} \right)=3r \\\\\\ \cfrac{50\cdot \ln\left( \frac{35}{23} \right)}{3}=r\implies 6.9976\approx r\implies \stackrel{\%}{7.00}\approx r[/tex]