Answer:
The average elevation of his three rest stop is 900 ft
Explanation:
The elevation at which the hiker started = 800 feet
The extra height to which he climbed on his first rest stop = 200 feet
The height down which he climbed to his second rest stop = 400 feet
The height to which he then climbed to his third rest stop = 500 ft
Given that the hiker started at 800 ft, we have;
His height at his first rest stop = 800 + 200 = 1,000 ft
His height at his second rest stop = 1000 - 400 = 600 ft
His height at his third rest stop = 600 + 500 = 1,100 ft
Therefore, the average elevation, hₐ, of his three rest stop is given as follows;
hₐ = (The sum of the three elevation)/(The number of elevation)
hₐ = (1,000 ft + 600 ft + 1,100 ft)/(3) = (2700 ft)/3 = 900 ft
The average elevation of his three rest stop = 900 ft.