I need to analyze the 2018 Balance Sheet and Income Statement of S&S Air, Inc. (Fundamentals of Corporate Finance - 12th edition, page 103-104). For the Income Statement, COGS Margin vs. Gross Margin; Gross Margin vs. EBITDA Margin; EBITDA Margin vs. EBIT Margin. (I had to delete the Balance Statement numbers, no space here). How to analyze the ratios? What they mean?

S&S AIR, INC.
2018 Income Statement
Revenue	$46,298,115
Cost of Goods Sold (COGS)	$34,536,913
Gross Profit	$11,761,202
Gross Profit Margin (%)	25.40%
Expenses
Selling and General Admin. (S,G & A)	$5,870,865
EBITDA	$5,890,337
EBITDA Margin %	12.72%
Depreciation & Amortization	$2,074,853
EBIT	$3,815,484
EBIT Margin (%)	8.24%
Interest	$725,098
Taxable Income	$3,090,386
Taxes (25%)	$772,597
Net Profit	$2,317,790
Net Profit Margin (%)	5.01%

Table 8.1 COGS Margin vs. Gross Margin	Value
COGS Margin	74.60%
Gross Margin	25.40%

Table 8.2 Gross Margin vs. EBITDA Margin	Value
Gross Margin	25.40%
EBITDA Margin	12.72%

Table 8.3 EBITDA Margin vs. EBIT Margin	Value
EBITDA Margin	12.72%
EBIT Margin	8.24%