Answer:
- See the graph with the curve attached

Step-by-step explanation:
# bags of # bushels Cost $
seeds
0 0 0
1 5 1 × 120 = 120
2 9 2 × 120 = 240
3 12 3 × 120 = 360
Pair # bags of seeds with cost
# bags of Cost $
seeds
0 0
1 120
2 240
3 360
Since the unit cost is constant, this is a linear function, which has the general form

Where m is the slope (the unit cost) and b is the y-intercep (the value when the number of bags is zero).
Thus the curve is modeled by the function:

Where C(x) is the cost and x is the number of bag of seeds.
To draw the curve, you can use the four points:
- (0,0)
- (1, 120)
- (2, 240)
- (3,360)
See the graph attached.