Requirement 1. Which of the preceding costs is variable? Fixed? Mixed? Explain. 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. Now determine the cost function for each cost. (Enter all values in the same format as the general linear formula. If an input field is not us Cost function Requirement 3. Combine the preceding information to get a monthly operating cost function for the Shamrock Corporation. Monthly operating cost = Requirement 4. Next month, Shamrock expects to use 470 machine hours, have 100 employees, and ship 9,300 units. Estimate the total operating cost for the month. Monthly operating cost =