Determine the average cost from the given data.
Svens Cookhouse is a popular restaurant located on Lake Union in Seattle. The owner of the restaurant has been trying to better understand costs at the restaurant and has hired a student intern to conduct an activity-based costing study. The intern, in consultation with the owner, identified three major activities. She then completed the first-stage allocations of costs to the activity cost pools, using data from last months operations. The results appear below:
Activity Cost Pool
|
Activity Measure
|
Total Cost
|
Total Activity
|
Serving a party of diners
|
Number of parties served
|
$12,000
|
5,000 drinks
|
Serving a diner
|
Number of diners served
|
$90,000
|
12,000 drinks
|
Serving a drink
|
Number of drinks ordered
|
$26,000
|
10,000 drinks
|
The above costs include all of the costs of the restaurant except for organization-sustaining costs such as rent, property taxes, and top-management salaries. A group of diners who ask to sit at the same table are 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.
Prior to the activity-based costing study, the owner knew very little about the costs of the restaurant. He knew that the total cost for the month (including organization-sustaining costs) was $180,000 and that 12,000 diners had been served. Therefore, the average cost per diner was $15.
Required:
Why do the costs per diner for the three different parties differ from each other and from the overall average cost of $15.00 per diner?