$18,000 at 9% compounded semiannually for 6 years?
The investment would be worth=$30,525.87 in 6 years @ 9% comp.S.A
The formula you use to calculate this is:FV=PV[1 + R]^N=FV OF $1 TODAY,
Where R=Interest rate per period, N=number of periods, PV=Present value, FV=Future value.