Nearly a tie: Australia and Greenland differ by barely -72%% in area — about 7,706,009 km² km² against 2,154,754 km² km².
Australia sits in Oceania, Greenland in North America. On the old Mercator map the latitude gap distorted how large each felt beside the other; at true size the answer is simply 0.3×.
The old map muddied it further: Mercator inflates Australia about 1.2× and Greenland about 11.8×, so on a Mercator-style map this pair appears 2.7× apart instead of the true 0.3×.
Australia fits 0× into Greenland.