EXERCISE 6-4 Applying the High-Low and Scattergraph Methods [LO2-CC9, 10) The following data relating to units shipped and total shipping expense have been assembled by Archer Company, a manufacturer of large, custom-built air-conditioning units for commercial buildings: Total Units Shipping Month Shipped Expense January 3 $1,800 February 6 2,300 March 4 1,700 April 5 2,000 May 7 2.300 June 8 2,700 July 2 1,200 Required: 1. Estimate a cost formula for shipping expense using the high-low method. 2. For the scattergraph method, do the following: a Prepare a scattergraph using the data given above. Plot total shipping expense on the vertical axis and units shipped on the horizontal axis. Fit a regression line to your plotted points by visual inspection b. Using your scattergraph, estimate the approximate variable cost per unit shipped and the approximate fixed cost per month 3. What factors, other than the number of units shipped, are likely to affect the company's total shipping expense? Explain your reasoning