Final answer:
To find the equivalent amount today to $10,000 4 years ago with 5.5% monthly compounded interest, use the compound interest formula to calculate the future value.
Step-by-step explanation:
To find the amount today that is equivalent to $10,000 4 years ago, we need to calculate the future value of $10,000 after 4 years of monthly compounding at a 5.5% interest rate.
Using the compound interest formula:
A = P(1 + r/n)^(nt)
where A is the future value, P is the principal amount, r is the annual interest rate, n is the number of times interest is compounded per year, and t is the number of years, we can plug in the values:
A = 10000(1 + 0.055/12)^(12*4)
Simplifying the equation will give us:
A ≈ $11,547.31
Therefore, the amount equivalent to $10,000 4 years ago is approximately $11,547.31, which is option b).