Total: 20 marks Below are the processing costs of Darnell Products observed over the last 10 months: Month Units Produced Processing Cost 1 7,500 $44,000 2 11,000 60,000 3 14,500 59,540 4 5,500 20,000 5 9,000 47,000 6 8,500 52,000 7 3,500 25,000 8 4,000 21,000 9 11,500 52,000 10 6,000 41,000 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. (15 marks) b- Predict the total processing cost if 18,000 units are produced. (5 marks)