The climber is on a hike. after 2 hours he is at an altitude of 200ft. after 6 hours he is at an altitude of 760ft. what is his rate of change?

Given two points (x₁,y₁) and (x₂,y₂) the rate of change is the slope (m) of the line
passes through these points.
m=(y₂-y₁)/(x₂-x₁)

We have two points:
(2,200)
(6,760)

Rate of change=m=(760-200)/(6-2)=560/4=140 ft/h

the rate of change would be 140 ft/h.