The table below represents the distance of an airplane from its destination as a function of time:
time (hours) x distance (miles) y
0 2700
1 2160
2 1620
3 1080
4 540

part a: what is the y-intercept of the function, and what does this tell you about the airplane? (4 points)

part b: calculate the average rate of change of the function represented by the table between x = 1 to x = 4 hours, and tell what the the average rate represents. (4 points)

part c: what would be the domain of the function if the airplane continued to travel until it reached its destination? (2 points)