Oklahoma is about 754 times bigger than Cook Islands.

Cook Islands is approximately 236 sq km, while Oklahoma is approximately 177,847 sq km, making Oklahoma 75,259% larger than Cook Islands. Meanwhile, the population of Cook Islands is ~8,128 people (3.7 million more people live in Oklahoma).
Tip: This to-scale comparison of Cook Islands vs. Oklahoma uses the Mercator projection, which distorts the size of regions near the poles.