Anyone can explain me how the gross profit % of sales is calculated?

Exhibit 5-1 MOCHA- Madison Dairy Ice VANILLA CHOCOLATE STRAWBERRY ALMOND TOTAL Cream Plant (March 2010): Total and Production and sales Product Profitability volume (gallons) 10,000 8,000 1,200 800 20,000 Unit selling price $3.00 $3.00 $3.30 $3.50 Sales $30,000 $24,000 $3,960 $2,800 $60,760 Direct materials 6,000 4,800 720 520 12,040 Direct labor 7,000 5,600 840 560 14,000 Overhead at 240% 16,800 13,440 2,016 1,344 33,600 Total factory expenses 29,800 3,840 3.576 2,424 59,640 Gross profit $200 $160 $384 $376 $1,120 Gross profit (% of sales) 0.7% 0.7% 9.7% 13.10 1.8%