Michigan Compiled Laws, Chapter 450. Corporations § 450.1523

Sec. 523. (1) A majority of the members of the board then in office, or of the members of a committee of the board, constitutes a quorum for transaction of business, unless the articles of incorporation or bylaws, or in the case of a committee, the board resolution establishing the committee, provide for a larger or smaller number. The vote of the majority of members present at a meeting at which a quorum is present constitutes the action of the board or of the committee, unless the vote of a larger number is required by this act, the articles, or the bylaws, or in the case of a committee, the board resolution establishing the committee.

(2) Amendment of the bylaws by the board requires the vote of not less than a majority of the members of the board then in office.