Answer:
The slope represents the rate of change of water volume stored in a storage tank.
The slope here is -900 in units of gallons per month. (gal/mos)
Step-by-step explanation:
The slope is rise over run, going from left to right.
Looking at the difference in time then, it is a period of ten months, and the volume difference is -9000 gallons.
The slope then is -9000 gallons divided by 10 months, which is -900 gallons per month