You do not have to complete question #4. Please explain! Thank you!

E21-30 Determining mixed costs-the high-low method Learning Objective 1 The manager of Quick Car Inspection reviewed the monthly operating costs for the past year. The costs ranged from $4,400 for 1,400 inspections to $4,200 for 1,000 inspections. 3. $4,300 Requirements 1. Calculate the variable cost per inspection. 2. Calculate the total fixed costs. 3. Write the equation and calculate the operating costs for 1,200 inspections. 4. Draw a graph illustrating the total cost under this plan. Label the axes, and show the costs at 1,000, 1,200, and 1,400 inspections. Iculating