A department of Alpha Co. incurred the following costs for the month of September. Variable costs, and the variable portion of mixed costs, are a function of the number of units of activity: 4,500 Activity level in units Variable costs Fixed costs Mixed costs $ 8,550 32,000 16,480 $57,030 Total costs During October, the activity level was 9,800 units, and the total costs incurred were $69,000. Required: a. Calculate the variable costs, fixed costs, and mixed costs incurred during October. Answer is complete and correct. October Variable cost Fixed cost Mixed cost $ 18,620 $ 32,000 $ 18,380 b. Use the high-low method to calculate the cost formula for mixed cost. (Do not round intermediate calculations and round your answers to 2 decimal places.) Answer is complete but not entirely correct. $ Cost formula $ 0.36 per 72,528.00% + unit