20-9-425. Trustees' consideration of validated petition proposing bond election. When a school district receives a school district bond petition from the county registrar, a meeting of the trustees shall be called for the consideration of the petition. The trustees shall be the judges of the adequacy of the petition, and their findings shall be conclusive against the school district in favor of the innocent holder of bonds issued pursuant to the election called and held by reason of the presentation of such petition. The petition shall be valid if the trustees find that it is in proper form and bears the signatures of not less than 20% of the school district electors who are qualified to vote under the provisions of 20-20-301.