Question

43
select the correct answer.
a group of scientists studied the invasion of a species in an area and its effect on the population of a native species. study the given data and determine the percent decrease in the native species population between years 1 and 2 and years 2 and 3.

	population of native species
year 1	7,950
year 2	3,460
year 3	1,380

a. 49.6% and 55.3%
b. 56.5% and 60.1%
c. 52.5% and 63.3%
d. 50.4% and 68.9%
e. 54.3% and 67.6%

Explanation:

Step1: Calculate decrease from Year 1 to 2

First, find the decrease: \( 7950 - 3460 = 4490 \).
Percent decrease formula: \( \frac{\text{Decrease}}{\text{Original}} \times 100 \).
So, \( \frac{4490}{7950} \times 100 \approx 56.5\% \)? Wait, no, wait: Wait, \( 7950 - 3460 = 4490 \). \( \frac{4490}{7950} \approx 0.5647 \), so \( 56.47\% \approx 56.5\% \)? Wait, no, wait the options: Wait, let's recalculate. Wait, Year 1: 7950, Year 2: 3460. Decrease: 7950 - 3460 = 4490. Percent decrease: (4490 / 7950) * 100. Let's compute 4490 ÷ 7950: 4490 ÷ 7950 ≈ 0.5648, so ~56.5%.

Step2: Calculate decrease from Year 2 to 3

Year 2: 3460, Year 3: 1380. Decrease: 3460 - 1380 = 2080. Percent decrease: (2080 / 3460) * 100. 2080 ÷ 3460 ≈ 0.6011, so ~60.1%.

So the two percentages are ~56.5% and ~60.1%, which matches option B.

Answer:

B. 56.5% and 60.1%