Andrew Forrest, Chairman, Fortescue Metals Group

Thanks to an internal party coup, Malcom Turnbull has become the country's fifth prime minister since 2010. The political turbulence comes at a tough time - the Australian economy is being hit hard by the slowdown in China and the slump in global commodity prices. Stephen Sackur talks to billionaire mining magnate Andrew Forrest and asks: has Australia squandered the riches that came with the resources boom of the early 21st century?