Adina is trying to decide how many workers she should hire at her new theater. The table below shows Adina's weekly costs and benefits based on the number of staff she hires. How many workers should she hire? Number of Workers Showings Total Benefits Marginal Benefit Total Costs Marginal Cost 3 21 $4,250 $3,920 4 25 $5,250 $1,000 $4,700 $780 5 28 $6,000 $750 $5,360 $660 6 30 $6,500 $500 $5,900 $540 7 31 $6,750 $250 $6,320 $420 four five six seven