The Fairport Machine Shop wants to develop a cost estimating equation for its monthly cost of

Question

electricity. It has the following data:

Cost of Electricity (Y)
$13,000
$15,000
$17,000
$14,500

Direct Labor-Hours (X)
1,500
1,700
2,000
1,600

What would be the best equation using the high-low method?

I think the answer is Y = $1,000 + $8X but when I went to confirm the equation by plugging in x and y values, the equation didn't hold true. Please help.