1. The commissioners appointed under sections 138.190 to 138.490 shall, within ten days after their appointment, meet at their offices in Jefferson City and enter upon the duties of their office.

2. A majority of such commission shall, at all times, constitute a quorum to transact business, and any vacancy shall not impair the right of the remaining commissioners to exercise all the powers of the commission so long as a majority remains.

3. Any investigation, inquiry or hearing which this commission is authorized to hold or undertake may be held or undertaken by or before any one member of the commission.

4. All investigations, inquiries, hearings and decisions of a commissioner, and every order made by a commissioner, when approved and confirmed by a quorum of the commission, if so shown on its record of proceedings, shall be deemed to be the order of the commission.