Final answer:
The cylinder fill weight for a 30 lb. DOT cylinder with a tare weight of 15 lbs. is 15 lbs.
Step-by-step explanation:
The cylinder fill weight for a 30 lb. DOT cylinder with a tare weight of 15 lbs. can be calculated by subtracting the tare weight from the total weight.
In this case, the cylinder fill weight would be 30 lbs - 15 lbs = 15 lbs.
Therefore, the cylinder fill weight for this cylinder is 15 lbs.