Joe owned a small repair shop. each day, he would check the mail to see if any of his customers mailed in a payment for the work he had done for them. some days, he would receive a check or two. at other times, he would have to wait days before getting another payment. what schedule of reinforcement is evident here?

The answer is "variable interval.

In operant conditioning, a variable-interval schedule is a schedule of reinforcement where a reaction is remunerated after a capricious measure of time has passed. This timetable creates a moderate, unfaltering rate of reaction.  

To see how a variable-interval schedule functions, we should begin by investigating the term itself. Schedule alludes to the rate of support conveyance, or how much of the time the fortification is given. Variable demonstrates that this planning isn't reliable and may fluctuate starting with one preliminary then onto the next. At last, interim implies that conveyance is controlled by time. In this way, a variable-interval schedule implies that support is conveyed at different and erratic intervals of time.

the answer is d i just took the test (provides the number of allowances an employee has claimed.)