Final answer:
The fixed ratio reinforcement schedule is characterized by a graph with "steps" due to reinforcement being delivered after a set number of responses, such as an eyeglass salesperson earning a commission after every few sales.
Step-by-step explanation:
The only schedule of reinforcement graph that has "steps" is the fixed ratio reinforcement schedule. This occurs because the reinforcement is delivered after a predictable number of responses, creating a pattern on the graph that looks like steps. For example, an eyeglass salesperson might receive a commission (reinforcement) each time they sell a certain number of glasses (predictable number of responses). After receiving the reinforcement, there may be a short pause before the salesperson begins working toward the next commission, hence producing a step-like pattern on a graph of response rates over time.