(Arbitration agreements signed by family members of persons admitted to elder care facilities are not binding on the persons so admitted absent evidence showing that those who signed the arbitration agreements had actual or apparent authority to act for the admittees. The signers’ statement that they had such authority is insufficient to create or evidence an agency relationship. Nor can equitable estoppel or unclean hands bar the admittees from denying they are bound by the arbitration agreements. The trial court did not abuse its discretion under CCP 1281.2(c) in denying the motion to compel arbitration as to the one plaintiff whose family member did have actual authority to sign the arbitration agreement. All the plaintiffs alleged the same claims arising from the same general conditions at the elder care facility so separate arbitration of one plaintiff’s claims would create a real risk of inconsistent results.)