Dugan Industries has collected the following monthly expense data for use in analyzing the cost behaviour of maintenance costs: Month Total Maintenance Costs Total Machine Hours January $5,000 400 February $ 6,000 500 March $ 7,200 700 $ 9,600 900 May $ 6,400 600 June $ 9,800 890 Use the high-low method to answer the following questions about Dugan Industries. Round your answers to two decimal places. April a) What is Dugan's variable cost component for maintenance costs? $ 9.6 per machine hour b) What is Dugan's fixed cost component for maintenance costs? $ 1160 c) What are the total expected maintenance cost when the activity level is 450 machine hours? $