If $19\mathrm{.}6$ lbs of sand is used to fill a standard cylinder $(6$ diameter x $12$ height$),$

and the max amount of water to be added to the sample without overflowing is $3\mathrm{.}67$ lb$.,$ calculate the

porosity of the sand sample. $(\backslash$rho w $=62\mathrm{.}4$ lb$/$ft$3)$