The scenario that involves a change modeled by a positive number, but an end result modeled by a negative number is:
Anthony starts his dive in a boat 6 feet above sea level. He descends to see a shipwreck 234 feet below sea level.
In this scenario, the change (the act of descending) is represented by a positive number (234 feet down), but the end result (the depth below sea level) is represented by a negative number (-234 feet).