Question 84·Hard·Command of Evidence
Heating Energy Required for Two Greenhouse Types Across Seasons
| Season | Heating energy consumed by glass greenhouse (kWh) | Heating energy consumed by polycarbonate greenhouse (kWh) |
|---|---|---|
| Winter | 8,900 | 4,300 |
| Autumn | 3,600 | 2,000 |
| Spring | 2,100 | 1,300 |
| Summer | 400 | 200 |
After monitoring two identically sized greenhouses through all four seasons, engineer Mei Nakamura concluded that installing rigid polycarbonate panels can cut seasonal heating energy needs by about half compared with using traditional glass. She defended this conclusion, noting that ______
Which choice most effectively uses data from the table to support Nakamura’s conclusion?
For SAT Reading & Writing questions that ask which statement best uses data to support a conclusion, first underline the key parts of the conclusion (what is being compared, over what time or conditions, and in what direction or magnitude, such as “about half”). Then, scan the table or graph and, if needed, quickly compute the relevant totals or ratios. Eliminate choices that only use part of the data (such as one season) or that fail to match the conclusion’s specific claim about magnitude. Finally, select the option that matches the conclusion’s scope and gives a direct numerical comparison.
Hints
Focus on the exact claim
Underline the key idea in Nakamura’s conclusion: she says polycarbonate panels can cut heating energy needs by about half compared with glass. Your supporting sentence must clearly show that kind of comparison.
Think about scope: one season or all seasons?
The description mentions monitoring the greenhouses through all four seasons. Which choice uses data that represent overall energy use across the year, not just a single season?
Look for a numerical comparison, not just a difference
You need evidence that one greenhouse used about half as much energy as the other. Which option gives numbers that directly show that relationship, rather than just giving a raw difference or an unquantified comparison?
Step-by-step Explanation
Understand what the conclusion is claiming
Nakamura concluded that installing rigid polycarbonate panels can cut seasonal heating energy needs by about half compared with using traditional glass.
This means the supporting evidence has to:
- Compare polycarbonate vs. glass.
- Look at energy use over the seasons as a whole, not just one season.
- Show that the polycarbonate greenhouse uses about half as much energy as the glass greenhouse.
Use the table to find total energy for each greenhouse
Add the energy consumption across all four seasons for each greenhouse.
For the glass greenhouse:
- Winter: 8,900
- Autumn: 3,600
- Spring: 2,100
- Summer: 400
Add them:
So the glass greenhouse used 15,000 kWh in total.
For the polycarbonate greenhouse:
- Winter: 4,300
- Autumn: 2,000
- Spring: 1,300
- Summer: 200
Add them:
So the polycarbonate greenhouse used 7,800 kWh in total.
Compare the totals and match the choice
Now compare the total energy use:
- Glass: 15,000 kWh
- Polycarbonate: 7,800 kWh
Find what fraction the polycarbonate total is of the glass total:
This means the polycarbonate greenhouse used about 52% as much energy as the glass greenhouse, which is a little over half, matching Nakamura’s claim that polycarbonate panels cut energy needs by about half.
Therefore, the best support is:
across all four seasons, the glass greenhouse consumed 15,000 kWh while the polycarbonate greenhouse consumed 7,800 kWh, so the polycarbonate model used roughly 52 percent as much energy as the glass model.