Why did the framers decide only 9 of 13 states would need to ratify the constitution rather than 13 of 13 needed for the articles of confedertation

How many citizens of mexico does it take to equal the ecological footprint of the average citizen of the united states? it takes nearly three mexican citizens to equal the ecological footprint of the average u. s. citizen. it takes about 12 mexican citizens to equal the ecological footprint of the average u. s. citizen. it takes just over eight mexican citizens to equal the ecological footprint of the average u. s. citizen. two citizens of mexico equal the ecological footprint of one average citizen of the united states. they are essentially equal?

Name one body of water the merchants traveled on

Describe the technology advancements that lead to explorers being able to sail great distances. [[ps: doesn't explain where. i am only speculating it's in europe.