Marco's unpaid credit card is $4332.75.

His APR is 18.6%.

What is his new balance if he made one new transaction for $432?

First, add the new transaction made to the previous unpaid credit card value. The sum will be,

$4764.75

Then, add the APR value by multiplying the amount above by 1.186. This will give us an answer of,

$5651