Algebra 1 8th Grade
posted by Leila .
According to the 1990 Census, the population of the United States was 2.49 x 10^8. The cost of taking the census in 1990 was 2.6 x 10^9 dollars. How much did the census cost per person in the United States?

take the population divides the cost

x per y means x/y
Therefore, cost per person means cost/person = 2.6x10^9/2.49x10^8 
Without parentheses, you would divide 2.6 x 10^9 by 2.49, then multiply that result by 10^8.
So at a minimum you need to use one set of parentheses:
2.6 x 10^9 / (2.49 x 10^8)