The number of blood tests performed and the related costs over the last nine months in Brentline Hospital are given below:

Month	Blood Tests Performed	Blood Test Costs
January		3,125		$	14,000
February		3,500		$	14,500
March		2,500		$	11,500
April		2,125		$	10,000
May		2,250		$	11,000
June		1,500		$	8,500
July		1,550		$	8,400
August		2,750		$	12,000
September		2,875		$	13,000

Required:

1. Using the highlow method, estimate the cost formula for blood tests.