Airline frequent flyer programs that reward customers with a free flight after every 50,000 miles of travel illustrate the use of a schedule of reinforcement.

a. fixed-interval

b. fixed-ratio

c. variable-ratio

d. variable-interval

Airline frequent flyer programs that reward customers with a free flight after every 50,000 miles of travel illustrate the use of a fixed-ratio schedule of reinforcement.

Fixed-ration schedule is when the reinforcement should be delivered after a fixed amount of correct responses. In this case, the fixed reinforcement is for every 50,000 miles of travel the person receives a free flight. This is set amount of miles that needs to be earned prior to receiving something in exchange.

Fixed interval

Explanation:

Schedule of reinforcement is a set of rule established to guide in responding to actions or delivering rewards.

Fixed interval of reinforcement is a form of reward scheduled to take place after attaining a set period of time and repeatedly on a fixed interval of time.It permits a regular rate of response at a greater intervals.

It attracts high response towards the end of the interval but slow response after reward is delivered.

answer(d) all of the choices are correct;