$7.$ A manager receives a forecast for next year. Demand is projected to be $600$ units for the first half

of the year and $900$ units for the second half. The monthly holding cost is $$2$ per unit, and it costs an estimated $$55$ to process an order. b$.$ why is it important to be able to assume that demand will be level during each six$-$month period. c$.$ If the vendor is willing to be offer a discount of $$10$ per order for ordering in multiplies of $50$ units, would you advise the manager to take advantage of the offer in either period?