a. Using the high-low method of cost analysis, determine the variable portion of the semi-variable cost per direct labor hour. Determine the total fixed cost component of the mixed cost. Isolate mixed costs: Do not use negative signs with your answers. High-Low Analysis: Round variable portion per unit to two decimal places, if applicable. Variable portion per unit: $ b. What should the total planned overhead cost be at 100,000 direct labor hours? Total planned overhead for 100,000 direct labor hours