I look at it more as numbers, so for example 1/2 can be simplified into 50, and 3/4 is 75/ 75 would be greater if it was positive. But, with there being a negative 1 in front of the answer, the lowest number closest to 0 is better. :D
The answer is: Reject H0. There is convincing evidence that the true mean weight of the chlorine tablets in the 50-pound buckets is less than 50 pounds.