Using the formula for the present value of a lump sum:
PV = FV / (1 + r/n)^(n*t)
where PV is the present value, FV is the future value, 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 need to find the present value of $11,500 discounted back 5 years, with an interest rate of 5.7% compounded semiannually, so:
PV = 11500 / (1 + 0.057/2)^(2*5)
PV = $8,547.81
Therefore, the present value of $11,500 discounted back 5 years with an appropriate interest rate of 5.7% compounded semiannually is $8,547.81.