The balance when $600 is invested for 3 years at 4.5 % p.a will be obtained using the formula:
A=P(1+r/100)^t
where:
P=principle
r=rate
t=time
thus plugging in the values in the formula we get:
A=600(1+4.5/100)^3
A=600(1.045)^3
A=$684.7
Answer: $684.7