Step-by-step explanation:
All your answers are correct.
Here is an explanation.
The descent is from 33,000 ft to 17,000 ft. The amount of the descent is
33,000 ft - 17,000 ft = 16,000 ft
It descended 16,000 ft in 8 minutes.
The rate of descent is
(16,000 ft)/(8 minutes) = 2,000 ft/minute
The initial altitude was 33,000 ft, so the graph starts showing an altitude of 33,000 ft at time equals zero minutes. Using the x-axis for time in minutes, and the y-axis for altitude in ft, this means the graph has point (0, 33,000) at its starting point. It is also the y-intercept.
The rate of descent is 2000 ft/minute. That rate is a descent, meaning it is a loss in altitude. Each minute that passes, the plane loses another 2000 ft of altitude. That means the rate is really a negative number, -2000 ft/minute
This rate is also the slope of the equation that expresses altitude as a function of time. The slope is -2000. The y-intercept is 33,000.
The equation in y = mx + b form is
y = -2000x + 33,000
where -2000 is the slope (a rate of descent of 2000 ft/min), and 33,000 is the y-intercept (meaning a starting altitude of 33,000 ft.)
If you still have questions, please ask in the comments.
