An analysis of maintenance cost at four levels of plant operations is shown below:

Hours	Cost	Hours x cost	Hours Squared
40	1,000	40,000	1,600
30	900	27,000	900
60	1,300	78,000	3,600
50	1,150	57,500	2,500
(total)180	4,350	202,500	8,600

The ABC uses the method of least square for splitting a semi-variable cost. How much is the fixed cost of the maintenance?

Group of answer choices

600

480

500

520