| Supplier | Active Accounts (millions) |
|---|---|
| British Gas | 7.5 |
| E.ON Next | 5.0 |
| OVO Energy | 4.5 |
| Octopus Energy | 4.0 |
| EDF Energy | 3.0 |
| Scottish Power | 2.5 |
| Independent/Others | 3.5 |
| Total | 30.0 |
Calculate the four-firm concentration ratio from the table above. You are advised to show your working.
92 exam-style questions on Edexcel A A Level Economics 3.4 Market structures, covering 3.4.1 Efficiency, 3.4.2 Perfect competition, 3.4.3 Monopolistic competition, 3.4.4 Oligopoly, 3.4.5 Monopoly, 3.4.6 Monopsony, and 3.4.7 Contestability. Each one has a worked solution and a mark scheme showing where the marks go.