How many pounds of scallop potatoes for 400?

I need more information to help you figure out how many pounds of scallop potatoes you need for 400 people! Please tell me:

* What kind of event is this? Is it a casual gathering, a formal dinner, a buffet, etc.?

* What other food will be served? Are the scallop potatoes the main dish or a side dish?

* How much are people likely to eat? Will they be hungry or just snacking on the side dish?

Once I have this information, I can help you estimate the amount of scallop potatoes you'll need.