The Ladder Company wants to develop a cost estimating equation for its monthly cost of electricity. It has the following data:

Month	Cost of Electricity	Direct Labor Hours
February	$8,100	750
May	9,000	850
August	10,200	1,000
November	8,700	800

Using the high-low method, which of the following is the best equation?

1. Y = $900 + $12.00X
2. Y = $900 + 8.40X
3. Y = $1,800 + $8.40X
4. Y = $2,400 + $8.4