Final answer:
The hiker's altitude has changed by 2682 feet from Badwater Basin, which is 282 feet below sea level, to an elevation of 2400 feet above sea level.
Step-by-step explanation:
The question asks how much the hiker's altitude has changed during his hike from Badwater Basin in Death Valley to an elevation of 2400 feet. To determine the change in altitude, we need to consider the starting and ending elevations. Badwater Basin is 282 feet below sea level, and the hiker has reached an elevation of 2400 feet above sea level.
To calculate the total change in altitude, we need to add the absolute values of the starting and ending elevations:
|(-282 feet)| + |2400 feet| = 282 feet + 2400 feet = 2682 feet.
Therefore, the hiker's altitude has changed by 2682 feet.