Required Use the high-low method to develop a cost-estimating equation for total annual operating costs. E15-19. Scatter Diagrams and High-Low Cost Estimation Assume the local Pearle Vision has the following information on the number of sales orders received and order-processing costs. Month Sales Orders 1 2 3 Order-Processing Costs $ 90,970 55,412 132,770 90,090 76,752 47,410 68,750 3,300 1,650 4,840 3,080 2,530 1,320 2,200 4 5 6 7. Required a. Use information from the high- and low-volume months to develop a cost-estimating equation for monthly order-processing costs. b. Plot the data on a scatter diagram. Using the information from representative high- and low-volume months, develop a cost-estimating equation for monthly production costs. c. What factors might have caused the difference in the equations developed for requirements (a) and (b)