.06 interest earned
x 3 years
-----
.18 total interest earned
$6,300.00 balance
x .18 total interest earned
--------------
$444.0000
+ $630.0000
------------------
$1,074.00 total interest
$1,074.00
+ $6,300.00
-----------------
$7,374 is the total balance in the account after 3 years.
Your answer is $7,374.