Suppose that the cost function for a product is given by Cx
     Suppose that the cost function for a product is given by C(x) = 0.002x3 + 8x + 6,912. Find the production level (i.e., value of x) that will produce the minimum average cost per unit C-(x). The production level that produces the minimum average cost per unit is  . (Round to the nearest whole number as needed.) 
  
  Solution
c-x =c(x) /x= 0.002x^2+8 +6912/x c\'-x =0.004x-6912/x^2=0 ==>x=120
