Note that 1 pound is equivalent to 16 ounces, while 1 ounce is equivalent to 0.0625 pounds.
Since the problem tackles converting pounds into ounces, we need to multiply the number of pounds to the number of ounces a pound is equivalent to, to get the total number of ounces.
Thus; 8.34 pounds * 16 ounces = 133.44 ounces. of water per gallon.
To check:
We can convert ounces back to pounds. Remember, 1 ounce is equal to 0.0625 pounds.
133.44 ounces * 0.0625 pounds = 8.34 pounds; the original weight stated in the problem.