$(i)$ The pressure of a gas is proportional to the mean speed of the molecules.
$(ii)$ The root mean square speed of the molecules is proportional to the pressure.
$(iii)$ The rate of diffusion is proportional to the mean speed of the molecules.
$(iv)$ The mean translational kinetic energy of a gas is proportional to its kelvin temperature.
$\left(\right.$ Given $\left.{k}_{{B}}=1.38 \times 10^{-23} \, {J} / {K}\right)$
(Fill the nearest integer).
