Question 88·Easy·Inferences
Nutritionists conducted an experiment to see whether the color of a plate influences how much salad people serve themselves. Participants were randomly assigned either a light green plate or a dark green plate and then helped themselves from identical bowls of salad. When the salads were weighed, those using the light green plates had taken, on average, 20% more salad than those using the dark green plates. The nutritionists concluded that the amount of salad people take may be affected by ______
Which choice most logically completes the text?
For SAT Reading & Writing questions that ask which option most logically completes a scientific or factual paragraph, first identify the variable that was changed (the cause) and the outcome that was measured (the effect). Then, choose the answer that cleanly links that cause to that effect without adding any new, unmentioned ideas. Quickly eliminate options that introduce factors not described in the experiment or that the passage does not give evidence for, focusing instead on the choice that directly summarizes the relationship the passage already shows.
Hints
Look at what changed between the two groups
Ask yourself: what was different for the people in one group compared with the people in the other group? That is usually what a scientific conclusion will focus on.
Connect the setup to the conclusion blank
The blank completes the idea "the amount of salad people take may be affected by _____." Think about which factor in the passage could reasonably be said to affect the amount of salad people took, based on what the researchers actually did.
Avoid new, unrelated ideas
Eliminate any answer choices that bring up information the passage never mentions or tests, such as different conditions or personal traits that were not part of the experiment description.
Step-by-step Explanation
Identify what the experiment changed
Read the description of the experiment and ask: What variable did the nutritionists deliberately change between the two groups? The passage says participants were randomly assigned either a light green plate or a dark green plate and then served themselves from identical bowls of salad. So the only thing that changed between groups was the plate color.
Identify what the experiment measured
Next, ask: What outcome did the nutritionists measure? The passage tells us that when the salads were weighed, those using the light green plates had taken, on average, 20% more salad than those using the dark green plates. So the measured outcome was how much salad participants took (the salad weight).
Understand what the conclusion must connect
The conclusion sentence says, "The nutritionists concluded that the amount of salad people take may be affected by ______." A logical scientific conclusion here must connect the variable they changed (from Step 1) to the outcome they measured (from Step 2). So we are looking for an answer choice that refers to the thing that was different between groups and that could explain the difference in the amount of salad taken.
Check each answer against the passage
Now compare each option with what actually happened in the experiment. The conclusion must be about the factor that differed between groups and was actually tested. Time of day (A), temperature of salad (C), and dietary preferences (D) are never mentioned as changing or being measured. Only one option names the tested variable that differed between the two groups and so could reasonably be said to affect how much salad people take: the color of the plate used.