Problem 6 - Prealgebra

Question

ANIMALS In 2000 , there were 356 endangered species in the United States Five years later, 389 species were considered endangered. What was the percent of change?

Step-by-Step Solution

Answer

The percent change in endangered species from 2000 to 2005 was approximately 9.27%.

Step 1: Identify the Initial and Final Values

To find the percent change, first identify the initial and final values. In this case, the initial number of endangered species in 2000 is 356, and the final number in 2005 is 389.

Step 2: Calculate the Change in Value

Subtract the initial value from the final value to find the change: \[389 - 356 = 33\]So, there was an increase of 33 species.

Step 3: Calculate the Percent Change

Use the formula for percent change:\[\text{Percent Change} = \left( \frac{\text{Change in Value}}{\text{Initial Value}} \right) \times 100\%\]Substitute in the values:\[\left( \frac{33}{356} \right) \times 100\% \approx 9.27\%\]

Step 4: Interpret the Result

The percent change is approximately 9.27%. This means that from 2000 to 2005, the number of endangered species in the United States increased by approximately 9.27%.

Key Concepts

Endangered Species

Endangered species are plants or animals that are at risk of becoming extinct. Extinction can occur due to various factors such as habitat loss, pollution, overhunting, and climate change. Conservation efforts aim to protect these species to maintain biodiversity. Understanding how the number of endangered species changes over time helps in assessing the effectiveness of conservation actions. For instance, if the number of endangered species increases, it may signal a need for stronger protective measures. Alternatively, a decrease could indicate successful conservation actions. Monitoring such changes is essential for guiding future efforts to protect our natural world.

Initial and Final Values

In any mathematical exercise involving change, identifying initial and final values is crucial. These values represent the starting point and the ending point, respectively. In the context of our exercise on endangered species, the initial value is the number of endangered species in 2000, which is 356. The final value is the count in 2005, which rose to 389. Recognizing these values helps us determine the extent of change over the specified period. By comparing these initial and final numbers, we can quantitatively understand how much a particular scenario, like the endangerment level of species, has altered over a given time frame.

Calculating Change in Value

Calculating the change in value is a straightforward step that helps quantify how much a particular number has increased or decreased over time. This is achieved by subtracting the initial value from the final value.For the endangered species scenario, the calculation is as follows:

• Final value: 389 (species in 2005)
• Initial value: 356 (species in 2000)

Subtract the initial value from the final value:\[ 389 - 356 = 33 \]The change in the number of endangered species is 33. This means that over the five-year period, the count of endangered species increased by 33.

Mathematics Problem Solving

Mathematics problem solving using percent change is a practical skill that helps convey the rate at which a quantity has increased or decreased. This provides a clearer perspective compared to absolute changes alone.To calculate the percent change, use the formula:\[ \text{Percent Change} = \left( \frac{\text{Change in Value}}{\text{Initial Value}} \right) \times 100\% \]Apply this formula to our exercise:

• Change in value: 33
• Initial value: 356

Substitute these values into the formula:\[ \left( \frac{33}{356} \right) \times 100\% \approx 9.27\% \]This calculation shows that the number of endangered species increased by approximately 9.27% from 2000 to 2005. Understanding percent change not only applies to biological studies but to various fields requiring analysis of growth or decline dynamics.