Simplify the following text for a Grade 8 native English-speaking person.
Original: Sir Arthur William Fadden , GCMG ( 13 April 1894 â `` 21 April 1973 ) was an Australian politician and , briefly , the 13th Prime Minister of Australia .
Simplified: Sir Arthur William Fadden ( 13 April 1895 â `` 21 April 1973 ) was the 13th Prime Minister of Australia .