You put $201 into a investment at 9% for four years. What will be the balance be at the end of four years?

Depends if it is compounding interest or not. But assuming it is:

$201 x. 09 = 18.09 (interest) = $219.09 (year 1)

$219.09 x. 09 = 19.72 (interest) = $238.81 (year 2)

$238.81 x. 09 = 21.49 (interest) = $260.30 (year 3)

$260.30 x. 09 = 23.43 (interest) = $283.73 (year 4)