Final answer:
The per-unit dollar disadvantage of purchasing the parts from the outside supplier is $13.
Step-by-step explanation:
To determine the per-unit dollar advantage or disadvantage of purchasing the parts from the outside supplier, we need to compare the unit product cost of producing the parts internally with the price offered by the supplier. The unit product cost of producing the parts internally is $38. The price offered by the outside supplier is $25 each.
Therefore, the per-unit dollar advantage or disadvantage of purchasing the parts from the outside supplier can be calculated by subtracting the price offered by the supplier from the unit product cost of producing the parts internally: $38 - $25 = $13 per unit disadvantage.