According to http://www.shgresources.com/ri/almanac/, Rhode Island has a total area of 1,545 square miles. 500 square miles of that is water, leaving 1,045 square miles of land.
1,045 sqare miles = 27,878,400 square feet.
6 billion people (every man, woman, and child on Earth) / 27,878,400 square feet = 215 people per square foot. That sounds a bit crowded.
As for Texas: (http://www.shgresources.com/tx/almanac/)
268,581 sq. miles total.
261,797 sq. miles of land.
7,298,481,484,800 sq. feet of land.
divided by 6 billion people =
1 person for every 1216 square feet, or a 35ft. x 35ft. plot of land for everyone.
So yeah, if every family on Earth had 8 people, each family would get 10,000 square feet of land.
Don't believe everything you think.
Your off on your calculation here is the correct figure:
1 045 square mile [survey, U.S. statute] = 29 133 044 865.916 12 square foot