The Hard Rock Mining Company is developing cost formulas for management planning and decision-making purposes. The companys cost analyst has concluded that utilities cost is a mixed cost, and he is attempting to find a base that correlates with the cost. The controller has suggested that tons mined might be a good base to use in developing a cost formula. The production superintendent disagrees; she thinks that direct labor-hours would be a better base. The cost analyst has decided to try both bases and has assembled the following information:

Quarter	Tons Mined	Direct Labor-Hours	Utilities Cost
Year 1:
First	28,000	6,300	$ 63,000
Second	18,000	4,300	$ 58,000
Third	33,000	5,300	$ 73,000
Fourth	25,000	7,300	$ 88,000
Year 2:
First	31,000	12,600	$ 133,000
Second	38,000	12,900	$ 138,000
Third	43,000	10,600	$ 98,000
Fourth	41,000	13,600	$ 138,000

1-a. Using tons mined as the independent variable, prepare a scattergraph that plots tons mined on the horizontal axis and utilities cost on the vertical axis.

1-b. Using the least-squares regression method, estimate the variable utilities cost per ton mined and the total fixed utilities cost per quarter. Express these estimates in the form Y = a + bX. (Round the Variable cost per unit to 2 decimal places and Fixed Cost to the nearest whole dollar amount.)