Sales of the firms in the tattoo industry are in the table.
Firm Sales (dollars per year)
Bright Spots ……………………………… 450
Freckles ………………………………….. 325
Love Galore ……………………………... 250
Native Birds ……………………………... 200
Other 15 firms …………………………… 800
Calculate the four-firm concentration ratio. What is the structure of the tattoo industry?