$1.$ A packing material used in a distillation column has an average diameter of $2$ centimeters.

Calculate its sphericity.

$2.$ A cube has a side length of $6$ centimeters. Calculate its sphericity.

$3.$ A glass marble has a diameter of $1\mathrm{.}2$ centimeters. Find its sphericity.

$4.$ A cylindrical canister has a diameter of $4$ inches and a height of $6$ inches. Calculate its

sphericity.

$5.$ A pellet used in a catalytic converter has a diameter of $4$ millimeters. Calculate its

sphericity.

$6.$ A particle of silica gel used in a drying process has a diameter of $0\mathrm{.}6$ millimeters. Calculate

its sphericity.

$7.$ A spherical watermelon has a diameter of $12$ inches. Calculate its sphericity.