The following data have been extracted from the records of Puzzle Incorporated: February August Production level, in units 8,100 16,200 Variable costs $ 17,820 $ ? Fixed costs ? 37,400 Mixed costs 19,593 ? Total costs $ 74,813 $ 105,026 Required: Calculate the missing costs. Calculate the cost formula for mixed cost using the highlow method. Calculate the total cost that would be incurred for the production of 12,150 units. Identify the two key cost behavior assumptions made in the calculation of your answer to part c.