Assume that a company wants to separate a mixed cost into its variable and fixed elements for cost estimation purposes. It provided the following information:

Week	Units Produced	Mixed Cost
1	12,000	$ 35,300
2	13,500	$ 39,500
3	14,000	$ 41,100
4	13,700	$ 39,620
5	11,500	$ 34,400
6	10,100	$ 32,050
7	10,800	$ 32,380
8	14,400	$ 41,890
9	11,200	$ 34,200
10	13,200	$ 39,150

Using least-squares regression, the estimate for the variable cost per unit is closest to: