Question

How much must the population of a species decrease over a ten-year period to be classified as endangered? 10% 50% 70% 20%​

Answer 1

To calculate the decrease in population over a ten-year period, we can use the formula:

`\displaystyle\sf \text{Decrease} = \left( \frac{\text{Final population} - \text{Initial population}}{\text{Initial population}} \right) * 100`

Let's calculate the decrease for each option:

1. Decrease for 10%:
`\displaystyle\sf \left( (-10)/(100) \right) * 100 = -10\%`

2. Decrease for 50%:
`\displaystyle\sf \left( (-50)/(100) \right) * 100 = -50\%`

3. Decrease for 70%:
`\displaystyle\sf \left( (-70)/(100) \right) * 100 = -70\%`

4. Decrease for 20%:
`\displaystyle\sf \left( (-20)/(100) \right) * 100 = -20\%`

Based on these calculations, the decrease of 20% would be the correct option.