Selecting a Basis for Predicting Shipping Expenses (Requires Computer Spreadsheet*) Boom Company assembles and sells portable speaker systems in the midwest. In an effort to improve the planning and control of shipping expenses, management is trying to determine which of three variables-units shipped, weight shipped, or sales value of units shipped-has the closest relationship with shipping expenses. The following information is available: Weight Sales Value of Shipping Month May June July August September October Units Shipped Shipped (Ibs.) Units Shipped Expenses $200,000$8,960 220,00012,320 160,000 10,400 228,000 16,640 280,000 13,760 320,000 13,120 6,000 10,000 8,000 14,000 2,000 9,000 9,300 12,000 12,150 15,000 10,500 12,000 Required