A company reports the following information about its sales and its cost of sales. Each unit of its product sells for $500. Using a scatter diagram, how would an estimated line of cost behavior be drawn based on the data? Would the cost be variable, fixed, or mixed?

Period Sales Cost of Sales Period Sales Cost of Sales

1 $ 22,500 $15,150 4 11,250 8,250

2 17,250 11,250 5 13,500 9,000

3 15,750 10,500 6 18,750 14,250