1. The problem statement, all variables and given/known data This is from a worksheet. I had to find the volume myself "A large number of spheres are poured into a graduated cylinder and gently vibrated until the occupy a minimum volume of 40 mL (or 40 cm^3). Use the information about close packing and the data you found to find the number of spheres in the cylinder. " I found -- volume = 0.0477 cm^3 diameter = 4.5 mm Given -- close packing fraction = .74048 2. Relevant equations Wasn't given one but I used (minimum volume) / (volume of a sphere) 3. The attempt at a solution 40 cm^3 / 0.0477 cm^3 = 839 spheres I'm not sure if I did was right. I don't know what I'm supposed to do with the information about the close packing fraction. I can't find it in my book.