George Caloz & Frres, located in Grenchen, Switzerland, makes luxury custom watches in small lots. One of the companys products, a platinum diving watch, goes through an etching process. The company has recorded etching costs as follows over the last six weeks:

Week	Units			Total Etching Cost
1		10			$	27
2		7			$	20
3		12			$	31
4		6			$	20
5		8			$	24
6		11			$	30
		54			$	152

For planning purposes, management would like to know the variable etching cost per unit and the total fixed etching cost per week.

2-a. Using the least-squares regression method, estimate the variable etching cost per unit and the total fixed etching cost per week.

2-b. Express these estimates in the form Y = a + bX.