Seifer Inc.'s inspection costs are listed below:

Units Produced

Inspection Costs

April

119

$

8,600

May

117

$

8,500

June

113

$

8,400

July

125

$

8,700

August

152

$

9,300

September

100

$

8,200

October

120

$

8,600

November

200

$

10,400

Management believes that inspection cost is a mixed cost that depends on the number of units produced. Using the high-low method, the estimates of the variable and fixed components of inspection cost would be closest to:

$22 per unit plus $6,000 per month

$14 per unit plus $8,000 per month

$25 per unit plus $5,400 per month

$18 per unit plus $6,800 per month