Compute a sales dollar base index for XYZ Sales, Inc., to analyze the following quality cost information, and prepare a memo to management. Make sure that you select an appropriate graph to show the quality costs over time!

Quarterly Costs (in thousands of dollars)

Compute a sales dollar base index for XYZ Sales, Inc., to analyze the following quality cost information, and prepare a memo to management. Make sure that you select an appropriate graph to show the quality costs over time! Quarterly Costs (in thousands of dollars) 1 2 3 4 Total sales 4,120 4,206 4,454 4,106 External failure 280.8 208.2 142.8 128.6 Internal failure 468.2 372.4 284.4 166.4 Appraisal 194.2 227.7 274.4 266.2 Prevention 28.4 29.2 50.2 80.2 Total quality costs 971.6 837.5 751.8 641.4