Answer:
If 275 gallon of oil tank costs $400 to fill.
Then 180 gallon of oil tank costs $261.8 to fill.
Explanation:
- Given that a 275 gallon of oil tank costs $400 to fill.
- We need to find how much it would cost to fill a 180 gallon oil tank.
- Use the unitary method to find the answer.
Step 1 of 2
If 275 gallon of oil tank costs $400 to fill.
Then the cost to fill 180 gallon of oil tank can be found by forming a proportion.
Let the required cost be x.

Multiplying both sides by 180 we get,

Step 2 of 2
To check if the answer is reasonable, we substitute it back in the formed proportion

We found x=$261.8 hence,

Hence, our answer is correct.