How much would $300 invested at 9% interest compounded monthly be worth after 3 years?

F=P (1 + (r/n)) ^ (nt)

F=future amount

P=present amount

r=rate in decimal form

n=number of times per year it is compounded

t=time in years

F=P (1 + (r/n)) ^ (nt)

F=future amount

P=300

r=0.09

n=1

t=3

F=300 (1 + (0.09/1)) ^ (1 (3))

F=300 (1+0.09) ^ (3)

F=300 (1.09) ^ (3)

F=388.509

it would be worth $388.51 (rounded)