Green Shade manufactures insulated windows. The firm's repair and maintenance (R&M) cost is mixed and varies directly with machine hours worked. The following data have been gathered from recent operations:

Month	MHs	R&M Cost
May	1400	9000
June	1900	10719
July	2000	10900
August	2500	13000
September	2200	11578
October	2700	13160
November	1700	9525
December	2300	11670

a. Use high-low method to estimate the total fixed cost component of the repair and maintenance cost. (

b. Use high-low method to estimate the variable cost per machine hour for repair and maintenance cost.

c. Use least-squares regression to estimate the total fixed cost component of the repair and maintenance cost. (Round-off to five decimal places)

d. Use the least-squares regression to estimate the variable cost per machine hour for repair and maintenance cost. (Round-off to five decimal places)