Mark is draining his pool to clean it. At 12:00 P.M., he started to drain the pool. At 4:00 P.M., the pool had 11,600 gallons of water. At 7:00 P.M., the pool had 6,800 gallons of water. If draining the pool is modeled by a linear function, how many gallons of water were initially in the pool?
