Question 26
[3 marks]
Andrew deposited $4 000 into an investment account which pays 1.5% p.a. interest. If
the interest is compounded quarterly, what will the balance of Andrew's account be after
5 years?



Answer :

To calculate the balance of Andrew's account after 5 years with an annual interest rate of 1.5% compounded quarterly, we can follow these steps:

1. Identify the initial amount (Principal):
- The initial amount deposited (principal) is [tex]$4,000. 2. Determine the annual interest rate: - The annual interest rate is 1.5%, which we convert to a decimal by dividing by 100, i.e., 0.015. 3. Identify the number of times interest is compounded per year: - Interest is compounded quarterly, which means it is compounded 4 times a year. 4. Calculate the interest rate per compounding period: - The interest rate per quarter is the annual interest rate divided by the number of compounding periods per year: \[ \text{Quarterly Interest Rate} = \frac{0.015}{4} = 0.00375 \] 5. Determine the total number of compounding periods: - Over 5 years, if interest is compounded quarterly, the total number of compounding periods is: \[ \text{Total Compounding Periods} = 4 \times 5 = 20 \] 6. Use the compound interest formula to calculate the balance: - The compound interest formula is: \[ A = P \left(1 + \frac{r}{n}\right)^{nt} \] - \(A\) is the amount of money accumulated after n years, including interest. - \(P\) is the principal amount ($[/tex]4,000).
- [tex]\(r\)[/tex] is the annual interest rate (0.015).
- [tex]\(n\)[/tex] is the number of times that interest is compounded per year (4).
- [tex]\(t\)[/tex] is the time the money is invested for in years (5).

7. Plug in the values:
[tex]\[ A = 4000 \left(1 + 0.00375\right)^{20} \][/tex]
[tex]\[ A = 4000 \left(1.00375\right)^{20} \][/tex]

8. Calculate the final balance:
- The calculated balance after 5 years is approximately [tex]$4310.93. Therefore, the balance of Andrew's account after 5 years will be approximately $[/tex]4310.93.