Magan invested \( \$ 210 \) in an account paying an interest rate of \( 9 \frac{5}{8} \% \) compounded quarterly. Myesha invested \( \$ 210 \) in an account paying an interest rate of \( 9 \frac{7}{8} \% \) compounded continuously After 9 years, how much more money would Myesha have in her account than Magan, to the nearest dollar?
Solución de tutoría real
Responder
Solución
Revisado y aprobado por el equipo de tutoría de UpStudy
The Deep Dive
To solve this problem, we first need to calculate the future value of both investments after 9 years. **Magan's Investment:** For Magan, who has an interest rate of \( 9 \frac{5}{8} \% = 9.625\% = 0.09625 \) compounded quarterly, we can use the formula for compound interest: \[ A = P \left(1 + \frac{r}{n}\right)^{nt} \] Where: - \( A \) is the amount of money accumulated after n years, including interest. - \( P \) is the principal amount (the initial amount). - \( r \) is the annual interest rate (decimal). - \( n \) is the number of times that interest is compounded per year. - \( t \) is the time the money is invested for in years. In this case: - \( P = 210 \) - \( r = 0.09625 \) - \( n = 4 \) (quarterly) - \( t = 9 \) Calculating Magan’s amount: \[ A_M = 210 \left(1 + \frac{0.09625}{4}\right)^{4 \times 9} \] \[ = 210 \left(1 + 0.0240625\right)^{36} \] \[ = 210 \left(1.0240625\right)^{36} \] \[ = 210 \times 2.4363 \approx 511.62 \] **Myesha's Investment:** Myesha's investment uses the formula for continuously compounded interest: \[ A = Pe^{rt} \] Where: - \( e \) is Euler's number (approximately equal to \( 2.71828 \)). - \( P \) is the principal amount. - \( r \) is the annual interest rate (decimal). - \( t \) is the time the money is invested for in years. For Myesha: - \( P = 210 \) - \( r = 9.875\% = 0.09875 \) - \( t = 9 \) Calculating Myesha’s amount: \[ A_Y = 210e^{0.09875 \times 9} \] \[ = 210e^{0.88875} \] \[ \approx 210 \times 2.4265 \approx 509.57 \] **Calculating the Difference:** Now, we can find the difference between Myesha's and Magan's totals: \[ \text{Difference} = A_Y - A_M = 511.62 - 509.57 \approx 2.05 \] After rounding to the nearest dollar, Myesha would have approximately **$2 more** than Magan.