A company uses the high low method to develop cost behavior equations. Assume the equations are driven by number of units. If the company expects a volume of 90 units, how would it calculate the total costs expected for a specific operating cost? by multiplying 90 by the expected total cost per unit by multiplying 90 by the average unit cost calculated using all data points available by dividing total expected fixed costs by 90 and then adding the expected variable rate per unit by multiplying 90 by the expected variable rate per unit and then adding total expected fixed costs by multiplying 90 by the expected fixed cost per unit and then adding total expected variable costs