At such public hearing any interested person, firm, association, or corporation may appear and present evidence or argument in support of or opposition to such petition. After such hearing and such independent investigation as may be deemed advisable, if the board finds that the proposed district and its proposed operation of an electric utility are feasible and conform to public convenience and welfare, the board shall thereupon and without delay issue a certificate in duplicate, setting forth a true copy of the petition and declaring that the petition has been approved. The board shall cause said certificate to be filed as provided in section 70-608, and thereupon such district under its designated name shall be and constitute a body politic and corporate and thenceforth shall be a public power district governed by all provisions of Chapter 70, article 6, and of other pertinent statutes, insofar as the same pertain to public power districts after their creation.