(4) At any meeting of the Commission the chairperson or acting chairperson and any 2 members shall form a quorum for the transaction of business. The chairperson or acting chairperson, as the case may be, shall have a deliberative as well as a casting vote. All decisions of the Commission shall be by a majority of the votes of the members present and voting. However, the chairperson, or acting chairperson, as the case may be, shall have a second or casting vote whenever the voting shall be equal.