After such hearing and upon such notice as the commission may prescribe, the commission shall enter its written order approving the petition and authorizing the proposed securities transactions unless the commission shall find that:
(1) such transactions are inconsistent with the public interest;
(2) the purpose or purposes thereof are not permitted by this part; or
(3) the aggregate amount of the securities outstanding and proposed to be outstanding would exceed the fair value of the properties and business of the public utility.