So for this problem we need to find the volume. The formula for volume is
l * w * h
40 * 20 * 5.5 = 4400
So now you need to put ft into yards
4400ft = 1466.667
Now multiply this by 12
1466.667 * 12 = 17600.004
Because you cant have $00.004 I believe that for this equation you would round to the nearest hundred, so that would be $17600.01.
Your answer is $17600.01