Answer:
1- Computation of the activity rate for the activities cost: 
     Activity Cost Pool           Activity Measure       Total Cost    Total Activity
Serving a Party of Diners   No. of Party's Served       $33,000    6000 parties
Serving a diner                Number of diners served   $138,000   15000 diners
Serving drinks                 Number of drinks ordered  $24,000   10,000 drinks
For first: 
 $5.5 per setup
For second: 
 $9.2 per hour
For third:  
 $2.4 drinks
- Above will be the cost break up for the party of four diners who order two drinks. A party of two diners who do not order any drinks. A lone diner who orders two drinks.
 
2- The cost per diner for three different parties differ from each other and the overall average cost $16 per diner  because this average cost does not include organization sustaining cost.