Could someone explain how they got the contribution margin of $19?

Total Order Incremental Analysis of Special Sales Order Decision Per Unit(17,000 units) 79 S 1,343,000 Revenue from special order Less variable expense associated with the order 60 1,020,000 Variable manufacturing costs Contribution margin Less: Additional fixed expenses associated with the order Increase (decrease) in operating income from the special order 323,000 19 323,000 Total Order Incremental Analysis of Special Sales Order Decision Per Unit(17,000 units) 79 S 1,343,000 Revenue from special order Less variable expense associated with the order 60 1,020,000 Variable manufacturing costs Contribution margin Less: Additional fixed expenses associated with the order Increase (decrease) in operating income from the special order 323,000 19 323,000