Nearly a tie: China and Greenland differ by barely -77%% in area — about 9,371,225 km² km² against 2,154,754 km² km².
China sits in Asia, 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 0.2×.
The old map muddied it further: Mercator inflates China about 1.6× and Greenland about 11.8×, so on a Mercator-style map this pair appears 1.7× apart instead of the true 0.2×.
China fits 0× into Greenland.