Question

mr. harrison gets paid once a month (at the end of the month) for the superb job of teaching/babysitting his students. his behavior is operating on a schedule of reinforcement. fixed-ratio variable-ratio fixed-interval variable-interval

Explanation:

Fixed - interval schedule of reinforcement occurs when reinforcement is provided after a fixed amount of time has passed. In this case, Mr. Harrison is paid once a month (a fixed time interval), so it fits the fixed - interval schedule. Fixed - ratio is based on a fixed number of responses, variable - ratio on a variable number of responses, and variable - interval on a variable time interval.

Answer:

Fixed - Interval