What is the cost per thousand gallons for a public water supply pumping 3,000,000 gallons in 30 days at a total expense of $8,770?

To determine the cost per thousand gallons for a public water supply, we first need to find the total amount of water pumped in thousands of gallons. Since the water supply pumped 3,000,000 gallons, we convert this to thousands by dividing by 1,000:

3,000,000 gallons ÷ 1,000 = 3,000 thousand gallons.

Next, we calculate the cost per thousand gallons by dividing the total expense by the number of thousands of gallons pumped:

Total expense: $8,770

Total gallons pumped (in thousands): 3,000

Cost per thousand gallons = Total expense ÷ Total gallons in thousands

Cost per thousand gallons = $8,770 ÷ 3,000 = $2.92.

Thus, the cost per thousand gallons for the public water supply is $2.92. This calculation demonstrates a direct relationship between the volume of water consumed and the total expenses incurred, enabling water utilities to manage and justify their pricing structure.