The commission shall promptly and duly organize. A majority of the commissioners shall constitute a quorum for the transaction of any business, for the performance of any duty or for the exercise of any power of the commission, and may hold meetings of the commission at any time or place within the state. Any investigation, inquiry or hearing which the commission has power to undertake or to hold may be undertaken or held by or before any commissioner. All investigations, inquiries, hearings and decisions of a commissioner shall be and be deemed to be the investigations, inquiries, hearings and decisions of the commission, and every order and decision made by a commissioner, when approved and confirmed by the commission and ordered filed in its office, shall be and be deemed to be the order of the commission.