What illustrates an example of fixed-ratio reinforcement?

Fixed-ratio reinforcement is a type of operant conditioning in which a response is reinforced only after a specific number of responses have been made. This means that the individual is rewarded after a predetermined set of actions, leading to a clear and predictable pattern of behavior.

The correct example, getting paid after every 5 sales, illustrates fixed-ratio reinforcement because the reinforcement (payment) is contingent upon making five sales, providing a clear and consistent ratio. This structure encourages the individual to increase their effort and productivity to reach the next reinforcement point, knowing precisely how many sales are needed to receive their reward.

In contrast, receiving a bonus after working indefinitely does not fit the fixed-ratio model, as there is no defined number of responses required before obtaining a reward. Similarly, being recognized for contributions on an irregular basis implies variable reinforcement without a set pattern or ratio of behavior leading to the reward. Winning a prize through a lottery also lacks a fixed ratio, as it is based on chance rather than a specific number of actions or responses required for the reward.