Final answer:
Derrick will receive $11,268.25 from his grandparents on his 18th birthday, which is the amount of $10,000 principal growing at 4% interest compounded quarterly over 3 years.
Step-by-step explanation:
When Derrick turned 15, his grandparents deposited $10,000 into an account with a 4% interest rate, compounded quarterly. To calculate how much money Derrick will receive on his 18th birthday, we can use the formula for compound interest:
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 form).
- n is the number of times that interest is compounded per year.
- t is the time the money is invested for, in years.
In Derrick's case:
- P = $10,000
- r = 4/100 = 0.04 (since the rate is a percentage, we convert it to a decimal)
- n = 4 (interest is compounded quarterly)
- t = 18 - 15 = 3 years
So the formula becomes:
Calculate the powers and the division inside the brackets, then multiply by the principal:
A = 10000(1 + 0.01)¹²
A = 10000(1.01)¹²
A = 10000(1.126825)
A = $11,268.25
Therefore, on his 18th birthday, Derrick will receive $11,268.25 from his grandparents.