this is based off fundamentals of cost accounting 4th ed. Chapter 4 Problem 57

Please explain your answer.

Decision to add shift to product more Basic and/or Formal Contribution margin per unit Additional labor cost at higher rate Hours to produce one unit Contribution per labor hour for extra cost New contribution margin per labor hour Demand (for profitable products only) Present production (from Requirement c) Amount to produce on new shift Contribution margin per unit of new production Additional operating profit (rounded)