Average maintenance costs are $1.50 per machine-hour at an activity level of 8,000 machine-hours and $1.20 per machine-hour at an activity level of 13,000 machine hours. If average maintenence costs equal total manufacturing costs divided by total activity then determine the following:

a. What is the total manufacturing cost at 8,000 machine hours?

b. What is the total manufacturing cost at 13,000 hours?

c. Using the high low method, complete the cost equation (y=a+b(x)) to determine total cost for 10,000 machine hours?