Consider an industry that has a total of six firms.

Firm	Units Produced
I	3280
II	1100
III	2820
IV	3800
V	1500
VI	500

The four-firm concentration ratio equals ______ percent.

Where this industry is located, the government defines an oligopoly as an industry where the concentration is at 80% or higher.The industry composed of the six firms above is or is not likely an oligopoly because