Why do you think Australia adopted the " Washminster"form of the polity?

In 1927,Canberra,Australia moved the capital.1931,the British Parliament passed the bill,,domestic and foreign affairs of Australia for autonomy,as the Commonwealth of Independent States.Australia in the name of the Heads of State of the king (or Queen),and the Queen appointed governor of the representative of the Australian government intervention is not the Governor.The Federal Government of Australia,a total of six States and the two territories (Northern Territory and the Capital Territory),the State has a Governor,is responsible for state affairs.The Australian Government House majority party or coalition parties,each session of the term of three years.The Government of the cabinet is the highest policy making body,there were 30 ministers.The supreme administrative leaders of the prime minister.