math
posted by kristen .
im doing corespondence and i tried for days to figure this out and i cant can anyone help??
Determine the amount of each investment? $400 at 9% compounded semiannually for 2 years i just need that answer and how too get it then i can do them thank you

All calculations are based on the assumption that $400 is the initial
investment. If that is not true,let
me know and I'll redo the cal. based
on the new INFO.
Pt = Po * (r + 1)^n
r = ((9 / 12)/ 100) * 6 = 0.045 = Semi
annual rate expressed as a decimal
n = 2 yr. / 0.5 = 4 = The number of
compounding periods.
Pt = 400 * (0.045)^4 = 477.01 = The
value of the investment after 2 yrs. 
i don't understand still please help with showing how you got that answer thank you