189k views
3 votes
Jan invests $8000 in a savings account. The account pays compound interest at a rate of x% per year. At the end of 6 years, there is a total of $8877.62 in the account. Work out the value of x. Give your answer correct to 2 decimal places.

User Sebcoe
by
8.4k points

1 Answer

0 votes

Final answer:

The annual compound interest rate (x%) for an investment of $8,000 that grows to $8,877.62 over 6 years is 1.75%, demonstrating the power of compound interest over time.

Step-by-step explanation:

We are tasked with determining the annual compound interest rate (x%) for an investment of $8,000 that grows to $8,877.62 over a period of 6 years. The general formula used for compound interest is A = P(1 + r/n)^(nt), where:

A is the amount of money accumulated after n years, including interest.

P is the principal amount (the initial amount of money).

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 our specific scenario, the formula modifies to 8877.62 = 8000(1 + x)^6. We assume that the interest is compounded once per year (n=1), so the new principal is compounded annually.

To solve for x, we first divide both sides by 8000, which gives us (1 + x)^6 = 1.1097025. We then take the sixth root of both sides to isolate (1 + x), which ultimately allows us to solve for x.

After calculating x, we find that the interest rate to two decimal places is approximately 1.75%. This showcases the impressive power of compound interest even at modest rates over several years.

User Igor Pashchuk
by
8.1k points