The commission may require all such persons as it deems necessary to appear personally and testify before it and to produce to it all books, records, files, papers, maps and documents as shall appear to be necessary for the purpose of formulating a reapportionment plan. The chairperson of the commission or any member thereof acting on behalf of the chairperson shall have power to administer oaths to persons summoned to appear before the commission and such persons may be questioned, under oath, concerning all matters necessary for the due execution of the duties vested in the commission by the Constitution and by this chapter. All hearings and proceedings shall be governed by this chapter and by rules of practice and procedure established by the commission. A majority of its membership shall constitute a quorum to do business, and the concurrence of a majority of its membership shall be necessary to make any action of the commission valid. Meetings shall be called and held at the call of the chairperson or by a quorum.