Variable cost per unit
Total sales 204,000 x $18 = $3,672,000
Gross margin (given) $816,000
COGS=Total Sales -Gross Margin ($3,672,000-816,000)= $2,856,000
Total Fixed Cost 204,000 x $9 = $1,836,000
COGS Total variable cost + total fixed cost 2,856,000-1,836,000=$1,020,000
variable cost per unit (1020,000/204,000)= $5
Contribution margin $2,652,000