How do I find COGSwith given information below?

How do I do the differential analysis to determine the return on investment and payback period for both residential parties

Type Birthday Parties/Year 1 Birthday Parties/Year 2 Birthday Parties/Year 3 Birthday Party average cost for 1 hr. Corp events 2hrs for 2 Disney Characters musical performance, pictures, games, dances and cottong candy 150 150 150 ii of Booked Events Average 10 shows per weekend 160 400 560 Birthday Party Sales 24,000 60,000 34,000 Cost of Goods Sold (Sales) 43,000 Contribution Margin 12,000 Differential Analysis Actor's Wages #Events x 40 x 2 Actors 12,800 32,000 44,800 Makeup #Events x 9.50 1,520 3,800 5,320 Cotton Candy 5% 1,200 3,000 4,200 Stuffed Animal Shells #Eventsx0.25x10 400 1,000 1,400 Cotton Fluff #Eventsx0.05x10 80 200 280 Fuel 2,500 2,501 2,502 Costume Cleaning #Events/5x10x2 640 1,600 2,240 Total Differential Outflows 19,140 44,101 60,742