Pleas explain the foContribution analysis formula for these solutions please

K-Even Analysis COLLARS LEASHES HARNESSES Sales Price 20.00 to 22.00 25.00 Fixed Costs 4,028 S 4,028 S 4,202 Contribution Margin 10.90 S 9.90 S 14.40 Break-Even Units (round up) 370.00 407.00 292.00 Target Profit 300.00 S 400.00 S 500.00 Break-Even Units (round up) 398.00 448.00 327.00 Target Profit 500.00 600.00 S 650.00 Break-Even Units (round up)