If a population dropped from 1,200 to 900, what is the percent decrease?

To determine the percent decrease in a population that dropped from 1,200 to 900, you first need to calculate the difference in the population. The difference is found by subtracting the new population (900) from the original population (1,200):

1,200 - 900 = 300

Next, you find the percent decrease by dividing the decrease (300) by the original population (1,200) and then multiplying by 100 to convert it to a percentage:

(300 / 1,200) * 100 = 25%

This calculation shows that the population has decreased by 25% from the original number. Thus, a 25% decrease is the correct answer, reflecting how much the population has shrunk in relation to its initial size.