Chessington Fitness Equipment produces a dumbbell set with a selling price of $1,000 per set. The costs to produce each set include: direct materials, $400; direct labor, $100, and variable manufacturing overhead, $100. The fixed manufacturing ofrhead per year is $12,000. There is no beginning inventory. If Chessington produces 250 sets and sells 210 sets, how much is operating income under variable costing? Assume no taxes. $72,000 $100,000 $84,000 $73,920 $88,000 Chessington Fitness Equipment produces a dumbbell set with a selling price of $1,000 per set. The costs to produce each set include: direct materials, $400; direct labor, $100, and variable manufacturing overhead, $100. The fixed manufacturing ofrhead per year is $12,000. There is no beginning inventory. If Chessington produces 250 sets and sells 210 sets, how much is operating income under variable costing? Assume no taxes. $72,000 $100,000 $84,000 $73,920 $88,000