Mo. Rev. Stat. § 360.025
Four members of the authority shall constitute a quorum for the purpose of conducting business. The exercise of the powers of the authority and action may be taken by the authority upon the affirmative vote of the lesser of four members or a majority of the members present as long as a quorum is present. Each meeting of the authority for any purpose whatsoever shall be open to the public, except as otherwise provided by law. Notice of meetings shall be given as provided in the bylaws of the authority. The proceedings and actions of the authority shall comply with all statutory requirements respecting the conduct of public business by a public agency. Members of the authority shall receive no compensation for services but shall be entitled to reimbursement for necessary expenses, including traveling and lodging expenses, incurred in the discharge of their duties. Any payment for expenses shall be paid from funds of the authority.
§ 360.025, RSMo