A group of diners who ask to sit at the same table is counted as a party. Some costs, such as the costs of cleaning linen, are the same whether one person is at a table or the table is full. Other costs, such as washing dishes, depend on the number of diners served. Data concerning these activities are shown below: Serving a Party Serving a Diner Serving Drinks Total Total cost $ 33,600 $ 142,000 $ 81,200 $ 256,800 Total activity 8,000 parties 20,000 diners 58,000 drinks Prior to the activity-based costing study, the owner knew very little about the costs of the restaurant. She knew that the total cost for the month was $256,800 and that 20,000 diners had been served. Therefore, the average cost per diner was $12.84 ($256,800 20,000 diners = $12.84 per diner)