Final answer:
Without the specific activity cost pool details and product activity levels, it's impossible to compute the unit product costs for products J78 and B52 using the activity-based costing system.
Step-by-step explanation:
To compute the unit product cost of Larner Corporation's products J78 and B52 using their activity-based costing system, you must first have detailed information about the costs that go into each activity cost pool, as well as the level of activity for each product in each of those cost pools.
The activity rates would help assign costs to each product based on the activities they consume. Unfortunately, the required details are not provided in the question which makes it impossible to compute the unit product costs for J78 and B52.
Understanding productivity and costs is crucial in business to ensure that the products are priced adequately to cover costs and achieve profits. Hence, accurate calculations are essential for effective pricing strategies, assessing labor costs, and maintaining desired profit margins in the business sector.