Ninet Marginal Cost A manufacturer incurs the following monthly costs in producing a water ski vests: 1) fixed monthly costs are S9,280AED; 2) unit production cost are S4AED per vest; and 3) equipment maintenance and repairs are generally AED per vest. A) What is the average cost for producing 1,200 vests? (5 Pts) ) What is the marginal cost for the 1.2009 vest produced? (SPS)