If the board, after the hearing, determines that the petition for inclusion of lands complies with the requirements of Article 2 (commencing with Section 75860) of this chapter and that the inclusion within the distict of the tract of land described in the petition, or some portion or portions thereof, will be for the best interests of the district, and if no protest against the inclusion of such land is made, or if such protest is made and enough signatures are withdrawn therefrom so that the protest is no longer sufficient, the board shall order the boundaries of the district to be changed so that the tract of land, or such portion or portions thereof as the board deems it for the best interests of the district to include, shall be included in the district.