Im having problems trying to figure out how to solve this problem.

The formula for Future Value of an Ordinary Annuity is

FV=PMT( (1+I)^n -1)/I)

The problem isFind the I (rate per period) and the N( number of Periods) for each annuity.

Quarterly deposits of $500 are made for 20 years into an annuity that pays 8% coumpounded quarterly.

fv=500((1+.08/4)^20-1)/.08

Since it is deposited quarterly do i multiply 500x4? and since it is compounded quarterly do I divide both interest by 4?

help! thanks