PCB Corporation manufactures a single product. Monthly production costs incurred in the manufacturing process are shown below for the production of 3,000 units. The utilities and maintenance costs are mixed costs. The fixed portions of these costs are $300 and $200, respectively.

                                                

Instructions
  (a) Identify the above costs as variable, fixed, or mixed.
  (b) Calculate the expected costs when production is 5,000 units.