Final answer:
To determine the time required for an investment to reach a specific value with compound interest, the compound interest formula is used. It will take approximately 21.7 years for an initial investment of $7,700 to grow to $44,700 at an annual interest rate of 8.25%, compounded annually.
Step-by-step explanation:
The question is asking how long it takes for an initial investment to grow to a specified amount given a certain annual interest rate. This is a problem that involves compound interest and can be solved using the formula for compound growth, which is A = P(1 + r/n)^(nt), where A is the final amount, P is the initial principal balance, r is the interest rate, t is the time the money is invested for, and n is the number of times that interest is compounded per year.
In this case, the money is compounded annually, so n = 1. We are given the initial amount (P = $7,700), the final amount (A = $44,700), and the annual interest rate (r = 8.25% or 0.0825 in decimal form). We need to find the time, t.
Let's rearrange the formula to solve for t:
44700 = 7700(1 + 0.0825)^t
Now, divide both sides by 7700:
5.8 = (1 + 0.0825)^t
To find t, we take the logarithm of both sides:
ln(5.8) = t * ln(1.0825)
Now divide both sides by ln(1.0825) to solve for t:
t = ln(5.8) / ln(1.0825)
Using a calculator, we find that t ≈ 21.7
Therefore, it will take approximately 21.7 years for the account value to reach $44,700, to the nearest tenth of a year.