Answer:
About 376.99 cubic inches
Explanation:
Cylinder has a volume of:

Where
V is the volume
r is the radius
h is the height
We need to find the volume of the cylinder, then multiply that answer by 3/4 to get the solution to this problem. First, the full volume of the cylinder.
Given
r = 4
h = 10
So,

Now, we multiply by 3/4:

Mary should be vase to 376.99 cubic inches