To solve this problem, use Boyle's Law, which states that the relationship between pressure and volume are inversely proportional.
Boyle's Law: P1 * V1 = P2 * V2
We are given the starting volume, and both pressures, so we can plug those numbers in.
(.428) * (2.5) = (.724) * (V2)
To solve for V2 first simplify:
1.07 = (.724) * V2
Then divide both sides by .724 to leave V2 behind
V2 = 1.478 (Rounded to 3 decimal places)
So the final volume is 1.478L