Sullivan Corporation wants to find an equation to estimate some of their monthly operating costs for the operating budget for 2021. The following cost and other data were gathered for 2020: E: (Click the icon to view the cost and other data) - X - Read the requirements. Data table .... Requirement 1. Which of the preceding costs is variable? Fixed? Mixed? Explain. Cost Month Cost Maintenance Health insurance Shipping costs function Mixed Fixed Explanation The cost neither remains constant in total nor remains constant per unit. Although the cost driver varies from month to month, the total cost remains constant The cost per unit remains constant each month. January February March Maintenance Machine Health Number of Shipping Units Costs Hours Insurance Employees Costs Shipped $ 4,580 158 $ 8,620 61 $ 22,103 7,130 $ 4,430 115 $ 8,620 82 $ 25,730 8,300 $ 4,690 239 $ 8,620 94 $ 24,614 7,940 $ 4,865 306 $ 8,620 106 $ 19,840 6,400 $ 5,195 466 $ 8,620 80 $ 18,337 5,915 Variable April May Requirement 2. Using the high-low method, determine the cost function for each cost. Begin by selecting the general formula that represents the linear cost function for each cost. June $ 4,733 283 $ 8,620 91 $ 28,551 9,210 4,968 339 y = a + bx $ 8,620 90 $ 27,156 8,760 370 $ 86 8,620 Maintenance Health insurance Shipping costs $ 26,071 8,410 y = a y = bx July $ August $ September $ October $ 4,915 5,055 427 $ 8,620 98 $ 21,018 6,780 5,215 475 $ 8,620 102 $ 22,103 7,130 Now determine the cost function for each cost. (Enter all values in the same format as the general linear formula. If an inpy November $ 5,230 515 $ 8,620 96 $ 17,422 5,620 Cost function December $ 4,710 274 $ 8,620 97 $ 30,008 9,680 Maintenance y = + y = + Health insurance Shipping costs y y = +