Answer:
The sharing cone holds about 9 times more popcorn than the skinny cone.
Explanation:
Cone volume:

r is the radius and h is the inches.
Skinny-size cone:
Radius is r, height h. So

Sharing size:
Radius is now 3r. So

How many times more popcorn?

The sharing cone holds about 9 times more popcorn than the skinny cone.