12 questions · Shuffled order · Progress saved locally when available
Identify the evidence for each answer and the specific flaw in its nearest competitor. Complete the four written drills in the lesson before this practice set. Question numbers follow the shuffled order; Guide question labels match the lesson references.
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The drill
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Question 5
Guide question 4.05
Foundation
Fourteen of the 20 surveyed volunteers supported extending the community garden's opening hours. The survey did not include other garden users.
Which conclusion follows?
Why this answer
Quantity and population
Correct choice: Most surveyed volunteers supported the extension.
Fourteen exceeds half of 20, so a majority of the surveyed volunteers supported the change.
A: The stated count is 14, not 20.
C: The unsurveyed users' views are unknown.
D: Other users might also support the extension.
If you missed it: Keep the denominator and the named population together.
Wear on the stone's edge is consistent with its having been used to scrape hides. Similar wear can also result from working plant fibers, so the object's precise use remains uncertain.
Which statement is supported?
Why this answer
Degree of certainty
Correct choice: Scraping hides is one possible explanation for the wear.
The passage identifies hide scraping as compatible with the evidence while retaining an alternative.
A: Two possible uses do not establish two actual uses.
B: The passage does not identify a primary use.
C: It gives no probability ranking between the explanations.
If you missed it: Distinguish a possible explanation from an established history.
Under the museum's rules, a painting may enter the loan program only after passing a condition inspection. Several paintings that passed inspection remain outside the program because their owners declined to participate.
Which statement follows?
Why this answer
Only and requirements
Correct choice: A painting entering the program in accordance with the rules has passed inspection.
Passing inspection is required for compliant entry, even though it does not guarantee entry.
A: Some passing paintings remain outside the program.
B: The passage explicitly provides passing paintings outside the program.
D: The inspection requirement has no stated owner-based exception.
If you missed it: Read 'only after' as a requirement, not a promise.
At the first survey, 42% of residents in East District and 68% in West District supported a proposal. At the second survey, support was 57% in East and 73% in West.
Which comparison is accurate?
Why this answer
Change versus final value
Correct choice: East's percentage-point increase was larger, although West's final support remained higher.
East gained 15 percentage points; West gained five. West still finished higher: 73% versus 57%.
B: A larger gain does not imply a higher final value.
C: Five is smaller than 15.
D: The reported final percentages differ.
If you missed it: Calculate changes and compare final values as separate tasks.
Among surveyed office workers, those who took walking breaks reported less afternoon fatigue. Workers chose whether to take breaks, and the study did not measure sleep duration.
Which conclusion is best supported?
Why this answer
Association and causation
Correct choice: Walking breaks were associated with less reported fatigue, but their causal effect was not established.
The survey reports an association. Self-selection and unmeasured sleep leave causal explanations unresolved.
A: It converts an association into prevention.
B: It asserts an unsupported reverse direction.
C: Sleep is a possible factor, not a demonstrated complete explanation.
If you missed it: Do not replace one unproven cause with another.
In this experiment, every seed exposed to both moisture and warmth germinated. Some seeds exposed to moisture without warmth also germinated.
Which interpretation follows?
Why this answer
Sufficient versus necessary
Correct choice: Moisture together with warmth was sufficient for germination among the tested seeds, but warmth was not necessary.
All tested seeds with both conditions germinated. Germination without warmth provides a direct counterexample to warmth being necessary. The sufficiency claim concerns this tested setup, not a universal guarantee for seeds in other conditions.
A: Some seeds germinated without warmth.
B: Some successes with moisture alone do not establish success for every seed.
C: No result for seeds without moisture is given.
If you missed it: Use a counterexample to reject necessity; preserve the experiment's limits.
Researchers randomly assigned 100 adult volunteers to practice remembering faces or to complete unrelated puzzles for two weeks. Immediately afterward, both groups took the same new-face recognition test; the face-practice group averaged a higher score. No later follow-up test was administered.
Which conclusion is best supported?
Why this answer
Direction, strength, and scope
Correct choice: The findings support better average performance from face practice than from puzzles on the immediate recognition test, without establishing a lasting benefit.
Random assignment supports attributing the average test-score difference to the assigned programs. The comparison concerns performance immediately after training; it does not measure lasting benefit or establish how much each person improved from a baseline.
A: Permanence requires evidence beyond the study period.
B: Participants were assigned rather than choosing groups.
D: A difference in group averages does not establish every individual's result.
If you missed it: Retain the causal evidence without expanding its outcome, duration, or individual scope.
For the sampled water, a test reliably detects compound Z whenever its concentration is at least 5 milligrams per liter. The properly performed test did not detect Z. It cannot reliably detect concentrations below that threshold.
Which conclusion is best supported?
Why this answer
Interpreting a negative result
Correct choice: The result supports a concentration below 5 milligrams per liter, while leaving open whether any Z is present.
Given the stated reliable threshold, non-detection supports a concentration below it. Zero and lower positive concentrations remain possible.
A: A low positive concentration could escape detection.
C: The test does not establish an exact below-threshold value.
D: The stated detection threshold makes the negative result informative.
If you missed it: Use the method's stated sensitivity instead of treating all missing evidence alike.