There were 3,904,532 persons usually resident in Queensland:

49.6% were males and 50.4% were females. (2006 Census)

There were 19,855,288 persons usually resident in Australia:

49.4% were males and 50.6% were females.  (2006 Census)

http://www.abs.gov.au/

Source: Australian Bureau of Statistics

The est. population of Queensland in March 2009 is 4,320,100

The est. population of Australia in March 2009 is 21,542,500

http://www.abs.gov.au/ausstats/abs@.nsf/mf/3101.0/

Source: Australian Bureau of Statistics

Comparisons:

Estimated 2009

1.    China- 1,338,612,000

2.    United States - 307,212,000

3.    Indonesia- 240,271,000

4.    United Kingdom- 61,113,000

5.     New Zealand - 4,213,000

6.     Papua New Guinea - 6,057,000

7.     South Africa - 49,052,000