Question 39·Hard·Command of Evidence
Distribution of Ecosystem Services Affected by Invasive Species by Service Type
| Region | Provisioning | Regulating | Cultural |
|---|---|---|---|
| Overall | 75% | 21% | 4% |
| West | 73% | 27% | 0% |
| North | 88% | 12% | 0% |
| South | 79% | 14% | 7% |
| East | 83% | 6% | 11% |
| Central | 33% | 67% | 0% |
To assess the impact of invasive species on ecosystems in Africa, Benis N. Egoh and colleagues reviewed government reports from those nations about how invasive species are undermining ecosystem services (aspects of the ecosystem on which residents depend). The services were sorted into three categories: provisioning (material resources from the ecosystem), regulating (natural processes such as cleaning the air or water), and cultural (nonmaterial benefits of ecosystems).
Egoh and her team assert that countries in each region reported effects on provisioning services and that provisioning services represent the majority of the reported services overall.
Which choice best describes data from the table that support Egoh and colleagues’ assertion?
For SAT Reading & Writing evidence questions with tables or charts, first restate the author’s claim in your own words and break it into parts (for example, "every region" and "majority overall"). Then, scan only the relevant column(s) and the overall row to verify each part of the claim using the numbers given. Finally, choose the answer that directly references data covering all required parts of the claim—eliminate choices that are true but talk about only some regions, only one category, or extra comparisons that do not address the exact assertion.
Hints
Understand what needs to be supported
Underline the two separate claims in Egoh and colleagues' assertion: one about each region and one about provisioning services being the majority overall.
Locate the relevant numbers
Focus on the Provisioning percentages in the table—for each region and for the Overall row. Ignore the regulating and cultural columns at first.
Connect the table to the words "each" and "majority"
Ask yourself: Does each region have some percentage listed for provisioning? And in the overall row, does provisioning make up more than half of all reported services?
Test the answer choices against both parts
For each option, check whether it gives evidence about every region and about provisioning being most of the services overall. Eliminate choices that only address one of these ideas or mention unrelated comparisons.
Step-by-step Explanation
Break the assertion into parts
Egoh and her team assert two things:
- Every region reports effects on provisioning services.
- Provisioning services make up the majority of the services reported overall.
Any answer choice that truly supports this assertion must give evidence for both parts, not just one.
Check the table for evidence of each part
First, look at the Provisioning column for each region:
- West: 73%
- North: 88%
- South: 79%
- East: 83%
- Central: 33%
All of these numbers are greater than 0, so each region has some reported effect on provisioning services.
Next, look at the Overall row:
- Provisioning: 75%
- Regulating: 21%
- Cultural: 4%
Provisioning services are clearly more than half (a majority) and larger than the other two categories.
Decide what a correct supporting statement must say
A correct answer must do both of these:
- Indicate that every region has some provisioning services reported (not just one or two regions, and not about another category like cultural).
- Indicate that provisioning services make up a majority overall, which the table shows as a much larger percentage than the other categories in the overall row.
Eliminate any option that only talks about a few regions or only mentions that provisioning is present without showing it is the majority overall.
Match the best answer to the table and the assertion
The only choice that clearly supports both parts of Egoh and colleagues' assertion is Choice B: it notes that no region's provisioning percentage is below 33% (showing that every region reports some provisioning services) and that provisioning services are 75% overall (showing they are the majority of reported services). Thus, the correct answer is: "None of the percentages shown for provisioning services are lower than 33%, and the overall percentage shown for provisioning services is 75%."