A local firm produces recliner sofas and wishes to expand production. The company currently employs sixteen workers who share twelve tool sets. Three months ago, they added two tool sets and production increased by eight recliner sofas per week. One month ago, they added four workers and production increased by eight recliner sofas per week. A tool set costs about three times what a worker costs. Would you recommend that the company hire an additional worker or purchase another tool set? Explain.