The situation that involves a change modeled by a negative number but an end result modeled by a positive number is:
Marissa had $64 in her savings account. She then withdrew $20 to buy some sandals.
In this situation, the act of withdrawing $20 is represented by a negative change (−$20), but after the withdrawal, Marissa ends up with $44, which is a positive number ($64 - $20 = $44).