The key to authority implied from course of conduct is the knowing acquiescence of the principal in the past acts. State on Inf. of Taylor v. American Ins. Co., 355 Mo. 1053, 200 S.W.2d 1 (banc 1946). "An agent's authority may be inferred when it appears that the agent has repeatedly performed acts like the one in question which the principal has ratified and adopted." Austin-Western Road Machinery Co. v. Commercial State Bank, 255 S.W. 585, 588 (Mo.App.1923).
Agency may be implied or inferred and may be circumstantially proved by conduct of the purported agent exhibiting pretense of authority with knowledge of the alleged principal coupled with acquiescence.