A firm uses two variable inputs, labor (L) and raw materials (M), in producing its output. At its current level of output: CL = $10 unit MP = = 25 Cu = $2 unit MPM = 4 a. Determine if the firm is operating efficiently, given that its objective is to minimize the cost of producing the current, given level of output b. Determine the changes necessary (if any) in the relative proportions of labor and raw materials needed to be made to operate efficiently