Question

The above figure represents the effect of efforts to reintroduce Chrysocyon Brachyurus, a wolf-like predator, to Uruguar. It tracks the population of both Chrysocyon Brachyurus and Sylvilagus brasiliensis, the rabbit species that is primary food-source.
Find the time-periods during which the Sylvilagus brasiliensis population undergo the greatest percent decline.

• A. ${}^{\prime }91{-}^{\prime }92$
• B. ${}^{\prime }93{-}^{\prime }95$
• C. ${}^{\prime }99{-}^{\prime }00$
• D. ${}^{\prime }00{-}^{\prime }01$

Answer 1

The correct option is D ${}^{\prime }00{-}^{\prime }01$

You need the formula for percent change:

$\frac{difference}{origional}\times 100$.

For choice (A), plug in a difference of about $200,000$ and an original of about $1,000,000$:

$\frac{200000}{1000000}\times 1000=20$.

This simplifies to $20\%$.

For (B), plug in a difference of about $200,000$ and an original of about $900,000$:

$\frac{2000000}{9000000}\times 1000=22.22$.

This simplifies to about $22\%$, so you can eliminate (A).

Choice (C) is incorrect because the Sylvilagus Brasilia population increased during that time.

If you chose (C), you may have calculated the percent change of the Chrysostom brachyurus population.

For (D), plug in a difference of about $200,000$ and an original of about $800,000$:

$\frac{2000000}{8000000}\times 1000=25$.

This simplifies to approximately $25\%$.

This is the greatest percent decrease.

Therefore, $00-01$ (D) is correct.