Chandler is on a hike in the woods. He has an altimeter with him, and Chandler uses it to measure his height above sea level at
various points in his hike. He starts out at 120.4 meters above sea level, then hikes up an additional 850.0 meters to the crest of a hill. Chandler takes a break, then hikes down into a valley that is 430.7 meters below the crest. How far above sea level, in meters, is Chandler when he is in the valley?
