The board at the time and place mentioned in the notice, or at such time or times to which the hearing of the petition may adjourn, shall proceed to hear the petition and objections thereto presented in writing by any person showing cause as aforesaid why the petition should not be granted. The failure of any person interested to show cause in writing, as aforesaid, shall be deemed and taken as an assent on his part to the granting of the petition. The board may at its discretion accept or reject the petition. If it deems it is for the best interest of the district that the petition be granted, it shall enter an order granting the petition and from and after such order the municipality shall be deemed to have acquired the water service as set forth in the order. If the petition is granted, the board shall determine the amount of money necessary to be raised by taxation from property within such municipality to pay the annual installments and a fair proportionate amount of estimated operating and maintenance charges for each succeeding year, as provided in the order granting the petition, and prepare a statement showing the tax rate to be applied to all property in such municipality, which rate shall be the rate fixed by resolution of the board modified to the extent necessary to produce from each such municipality only the amount of money apportioned thereto in the resolution, less any amount paid or undertaken to be paid by such municipality in cash or as credited thereto by payments from the general funds of such municipality. Upon receipt by the county board of each county, wherein such municipality is located, of a certified copy of such resolution showing the tax rate to be applied to all property in each municipality and showing the municipalities and the property which is exempt therefrom, if any, it shall be the duty of the county officers to levy and collect such tax in addition to such other tax as may be levied by such county board at the rate so fixed and determined.