Math
posted by Anonymous .
Ed long promised to pay is son $400 semiannually for 12 years. Assume Ed can invest his money at 6 % in an ordinary annuity. How much must Ed invest today to pay his son $400 semiannually for 12 years?

i = .06/2 = .03
n = 24
Present value = 400(1  1.03^24)/.03
= ....
you do the buttonpushing 
12 years x2 =24periods
6%/2=3%
24 periods @3%
400 x 16.9355= $6,774.20