Hi, re TY, see Note:
Note: In General:
A = Accumulated Amount
P= principal = $353 , $655
r= annual rate = .05, .06
m= periods per year = 12 , 12
t= years = 4 , 4
Calculator makes short work of the answer.
:The sum listed(for the 1st 4 yrs + 2nd 4 years) gives the Amount after 8 years