Final answer:
The initial question about the activity-based overhead rate per purchase order cannot be answered without specific direct costs and the total amount of purchase orders. However, the average fixed cost is discussed, which represents overhead spread over units of output, resulting in a hyperbolic curve that decreases as production increases.
Step-by-step explanation:
The question pertains to calculating an activity-based overhead rate related to purchase orders. However, the provided information seems to describe the concept of average fixed cost, which is the overhead or fixed cost divided by the quantity of output produced. If the fixed cost is $1,000, the average fixed cost will decrease as output increases, due to the fixed cost being spread over more units. This phenomenon is known as spreading the overhead. The average fixed cost curve represents this relationship and typically appears as a hyperbolic curve, starting high when production levels are low and moving downwards as production increases.
To directly answer the question, we would need different information, specifically direct costs associated with each purchase order and the total amount of purchase orders to determine the activity-based overhead rate per purchase order. The information provided does not allow for the calculation of this rate.