compound that must be kept in an environment where both temperature and humidity can be controlled. He uses $250$ pounds per month of the chemical, estimates the holding cost to be $4\mathrm{.}25($because of spoilage$),$

and estimates order costs to be

$1-4950-99100-149150-249250-349350-499500+$

$1-99100-199200-399400-499500+$

$20$ per order. The cost schedules of four suppliers are as follows: