Question 4: High-Low Time: 15 minutes Total: 10 marks Below are the processing costs of Darnell Products observed over the last 10 months: Month Units Produced Processing Cost 7.500 S44.000 11.000 14,500 58.000 + 5.500 20000 S 9,000 47.000 8.500 52.000 7 3.500 25,000 IS 7,000 41.000 19 11.500 $2.000 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. (6 marks) b. Predict the total processing cost if 22,000 units are produced. (4 marks)