Five years ago the population at Liberty Middle School was 1,600 students. This year the population is 1,250 students. Use the expression N-P/5 where N represents this year’s population and where P represents the previous population to find the average change in population each year.

Answer 1

To find the average change in population each year using the expression \( \frac{N - P}{5} \), we first need to identify the values for \( N \) and \( P \):

• \( N \) (this year's population) = 1,250 students
• \( P \) (population five years ago) = 1,600 students

Now, we can substitute these values into the expression:

\[ \frac{N - P}{5} = \frac{1,250 - 1,600}{5} \]

Calculating the subtraction in the numerator:

\[ 1,250 - 1,600 = -350 \]

Now substituting this value back into the expression:

\[ \frac{-350}{5} = -70 \]

Thus, the average change in population each year is \(-70\) students per year. This means that, on average, the school's population has decreased by 70 students each year over the past five years.