The formula for annual compound interest, including principal sum, is:
where
A = the future value of the investment/loan, including interest
P = the principal investment amount (the initial deposit or loan amount)
r = the annual interest rate (decimal)
n = the number of times that interest is compounded per year
t = the number of years the money is invested or borrowed for
Here, we have to find semi-annually
Therefore,
Hence, the amount owed after 6 years is $4139.78.