The management of Colfax Manufacturing Inc. uses cost information from job sheets to assess its performance. Information on the total, product type, and quantity of items produced is as follows:

a. Develop a graph for each product (three graphs), with Job No. (in date order) on the horizontal axis and unit cost on the vertical axis. Use this information to determine Colfax Manufacturing’s cost performance over time for the three products.
b. What additional information would you require to investigate Colfax Manufacturing’s cost performance more precisely?