Hello
The equation to find the volume of a cube is a^3 Our a is 4, which means that our equation is 4^3 4 to the power of 3 is 64, which gives us our volume.
Lastly we must do 64x3,which gives us 192. This means the third box has a volume of 192in^3.
I HOPE THIS HELPS & GOOD LUCK!!! <3