Answer:
Read this prompt for an informative essay. The Food and Drug Administration (FDA) provides a number of services to the American public.
Hope this helps.
Aztecs were a Mesoamerican Indian culture that was devastated by Cortez and the Spanish in the 1520s.
Which of the following best defines a nation-state?
A. A country where most inhabitants are of the same ethnicity
In most nation-states inhabitants often share ethnicity/origin and language.
Answer:

Explanation:
Data provided in the question
The ratios are
Second graders to the fourth grader is 
First graders to the second grader is 
Third graders to the fourth grader is 
Now if we multiplying these above three ratios but the last ratio should be reverse
So, it would be
= 
= 
Hence, the ratio of first graders to the third graders is 