help in figuring equation (increading and decreasing)

[The following information applies to the questions displayed below.] Martinez Company's relevant range of production is 7,500 units to 12,500 units. When it produces and sells 10,000 its average costs per unit are as follows: 5. If 8,000 units are produced and sold, what is the total amount of variable costs related to the units produced and sold? Note: Do not round intermediate calculations