Question

According to the 2010 census data , the population of Texas was about 2.5*10^7 people. The land area of Texas is about 2.6*10^5 m^2. whats the average number of people in square miles in 2010? I think the answer is 9.6x10^12. Will someone please check my work?

Answer 1

Always do a sanity check. There are approximately 7 billion people on the earth. That's 7*10^9. So how could you have 10^12 per square mile in Texas?!?!?

people/mi^2 means divide population by area.

2.5*10^7 / 2.6*10^5 = 0.96 * 10^2 = 96 people/mi^2

you appear to have (sort of) divided the numbers, but you added the exponents, rather than subtracting.

Answer 2

thank you it made that much easier to understand that the answer is 9.6x10^1

Answer 3

It would help if you proofread your questions before you posted them.
10^1 is not area. Did you read oobleck's answer?

Answer 4

eh, PsyDAG? The number is correct. 9.6*10^1 = 96 is the right answer in people/mi^2.

I do agree, however, that there is a typo in the question, since the area of Texas should have been in mi^2, not m^2. 96 people/m^2 would also be pretty crowded!

and "average number of people in square miles" is wrong syntax.