The State Board of Education, within ninety days after the receipt of any petition described in section 79-1208, shall hold a public hearing on the proposed reorganization plan. At the board's option, it may appoint a hearing officer to conduct the public hearing and issue a summary of the evidence presented. The board may also direct the appointed hearing officer to recommend a decision to the board, which recommendation shall not be binding on the board. Within one hundred twenty days after the receipt of such petition, the board shall approve or reject such petition. If the board rejects the petition, it shall clearly state its reasons for such rejection. Approved petitions for reorganization of educational service unit boundaries shall be referred to the appropriate county and educational service unit officials to implement the plan and to make the necessary changes in the educational service unit maps and tax records.