If a storage tank that measures 12 feet by 9 feet by 8 feet is designed to store gas that costs $1.82 per cubic foot, what does it cost to fill the tank to one-half of its capacity?

For this case, the first thing to do is find the volume of the tank.
 We have then:
 V = (12) * (9) * (8)
 V = 864 feet ^ 3
 Then, the cost of filling half the tank is given by:
 C = (1/2) * (1.82) * (864)
 C = 786.24 $
 
 It costs to fill the tank to one-half of its capacity about:
 C = 786.24 $

The correct awnser is 29.76 pounds.