Final answer:
To accumulate $90,000 in three years in an account with a 5.5% interest rate compounded quarterly, approximately $75,874.67 must be initially deposited.
Step-by-step explanation:
To find out how much needs to be deposited in a bank paying a compound interest rate of 5.5% per year, compounded quarterly, to have $90,000 at the end of 3 years, we use the formula for compound interest:
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 deposited).
- 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 deposited for, in years.
We want to find P when A = $90,000, r = 0.055 (because 5.5% = 5.5/100 = 0.055), n = 4 (because the interest is compounded quarterly), and t = 3.
The formula becomes:
$90,000 = P(1 + 0.055/4)(4*3)
Now we solve for P:
$90,000 = P(1 + 0.01375)12
$90,000 = P(1.01375)12
P = $90,000 / (1.01375)12
Using a calculator:
P ≈ $90,000 / 1.186384
P ≈ $75,874.67
Therefore, approximately $75,874.67 should be deposited to have $90,000 in three years.