Salter Corporation wants to find an equation to estimate some of their monthly operating costs for the operating buaget for 2021. The following cost and other data were gathered for 2020: (Click the icon to view the cost and other data) Read the Although the cost driver varies from month to month, the total cost remains constant. The cost per unit remains constant each month. 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. Requirements 1. Which of the preceding costs is variable? Fixed? Mixed? Explain. 2. Using the high-low method, determine the cost function for each cost. 3. Combine the preceding information to get a monthly operating cost function for the Salter Corporation. 4. Next month, Salter expects to use 420 machine hours, have 120 employees, and ship 9,100 units. Estimate the total operating cost for the month