Below are the processing costs of Hartley Products observed over the last 12 months: Month Units Produced Processing Cost 1 8,500 2 3 14,000 15,000 5,500 9,000 4 $51,000 57,000 60,000 38,000 53,000 52,000 33,100 41,000 5 6 8,500 3,800 7 8 7,000 9 12,500 6,000 54,000 40,000 10 11 6,600 7,100 40,600 42,000 12 a. Use the high low method to determine the variable cost per unit and fixed cost per month. Express your results in the form of a linear equation y = a + bx. b. Predict the total processing cost if 13,000 units are produced. C. Why do we use high low method