Match the schedule of partial reinforcement to the correct description.
1) based on the amount of time that must pass before a behavior is rewarded
2) the number of behaviors or the amount of time that must pass before the reward is always the same
3) the required number of behaviors or the amount of time that must pass before the reward is unpredictable from the perspective of the learner
4) relies on the number of behaviors that must be performed prior to the reward