Math
posted by Annie .
Dieter deposists $ 9000 inoan account that pays 10%/a compunded quarterly, after 3 threes the inerest rate changes to 9%/a compounded semiannually, calculate the value of his investments 2 years after this change

I'm assuming you mean the rate changes to 9 % after 3 years.
Pt = Po(1+r)^n.
r = (10%/4) / 100% = 0.025 = Quarterly % rate exprssed as a decimal.
n = 3 yrs * 4 comp / yr. = 12 Comp. periods.
Pt = $9000(1.025)^12 = $12,104 After 3
years.
r = (9%/2) / 100% = 0.045 = Semiannual
@ rate expressed as a decimal.
n = 2 Comp./yr * 2 yrs = 4 Comp.periods
Pt = $9000(1.045)^4 = $10.732.67.
Total value = $12,104.00 + 10,732.67 =
$22,836.67. 
Correction:
Pt = $12,104(1.045)4 = $14,434.25. =
Total value after 5 years. 
Correction:
Accumalated Value = $12,104(1.045)^4
= $14,434.25.
(total value after 5 years