points) Archer Company is a wholesaler of custom-built air-conditioning units for commercial buildings. It gathered the following monthly data relating to units shipped and total shipping expense: Month January February March April May June July Units ShippedTotal Shipping Expense S 1,800 $ 2,300 $ 1,700 $ 2,000 S 2,300 $ 2,700 $ 1,200 6 2 Using the high-low method, calculate the equation of a cost line for the shipping expense for this company (Y -a+ bX) Required