Cullumber Fumiture currently manufactures rocking chairs as its main product. Each chair uses one seat cushion and one back cushion with the following costs per set of cushions (one seat and one back): Shepert Company has contacted Cullumber with an offer to sell it 4,200 sets of cushions for $26 each. If Cullumber buys the cushions. $4 of the frxed overhead per unit will be allocated to other products. Should Cullumber make or buy the cuthions? Cullumber should to saves perset