At the trial the court shall determine whether the board of county commissioners has acted within its discretion and has correctly construed and applied the law. If it finds that it has, the finding of the board shall be affirmed; otherwise it shall be reversed or modified. The judgment of the court may change, confirm, correct, or modify the values of the property in question as shown upon the roll, and a certified copy thereof shall be filed with the county treasurer, who shall change, modify, or correct the roll as and if required by the judgment.