In counties of the third to eighth classes, the budget shall reflect as nearly as possible the estimated revenues and expenditures for the year for which it is prepared. It shall be prepared on forms prepared and furnished as provided in this act. The commissioners shall, upon adopting the budget, adopt the appropriation measures required to put it into effect and shall fix such rate of taxation upon the valuation of the property taxable for institution district purposes as will, together with all other estimated revenues of the district, raise a sufficient sum to meet the said expenditures. Within fifteen days after the adoption of the budget, the commissioners shall file a copy thereof in the office of the Department of Internal Affairs.