You know that at 10:00, there are 304 ounces; at 12:00, there are 228; at 3:00, there are 114 ounces; and so on. You can convert these to be like points on a graph: (10,304), (12,228), (15,114).
If you find the slope, then you will have the amount of water that leaks out the bucket every hour.
M=(228-304)/(12-10)= -38
Thus, 38 ounces of water leak from the bucket every hour.