CCTST Inference 4 — Questions and Answers
Question 1: A poll shows 55% of respondents support a policy, with a margin of error of ±4%. What can be inferred about actual public support?
- Exactly 55% of the public supports the policy.
- Public support is likely between 51% and 59%. (Correct answer)
- A majority will definitely support the policy.
- The poll is too unreliable to use.
Correct answer: Public support is likely between 51% and 59%.
Applying the margin of error to the reported figure gives the plausible range of true population support.
Question 2: Premises: 'All squares are rectangles. Shape X is not a rectangle.' What can be inferred about Shape X?
- Shape X is a circle.
- Shape X is not a square. (Correct answer)
- Shape X is a rectangle.
- Shape X might still be a square.
Correct answer: Shape X is not a square.
If being a rectangle is required for being a square, then anything that is not a rectangle cannot be a square.
Question 3: A company's profits rose 10% after a new CEO was hired. An analyst infers the CEO caused the increase. Which fact would most weaken this inference?
- The CEO has an MBA from a top university.
- The entire industry experienced 12% profit growth over the same period. (Correct answer)
- The CEO restructured the sales department.
- Employees reported higher morale after the hire.
Correct answer: The entire industry experienced 12% profit growth over the same period.
If the whole industry grew even more, the company's gains may reflect market trends rather than the CEO's leadership.
Question 4: Which statement is an inference rather than an observation?
- The thermometer reads 98°F.
- The patient is feverish and fighting an infection. (Correct answer)
- The patient's skin feels warm to the touch.
- The doctor noted a temperature of 98°F in the chart.
Correct answer: The patient is feverish and fighting an infection.
Concluding the patient is feverish and fighting infection goes beyond direct measurement and involves interpretation.
Question 5: Sales of umbrellas in a city spiked last Tuesday. What is the most reasonable inference?
- A famous celebrity endorsed umbrellas on Monday.
- It rained or was forecast to rain around that time. (Correct answer)
- Umbrellas went on sale at all major stores.
- The spike was a data entry error.
Correct answer: It rained or was forecast to rain around that time.
Increased umbrella sales most commonly occur when rain is expected or occurring, making weather the most parsimonious explanation.
Question 6: A study reports that students who eat breakfast perform better academically. A teacher concludes that serving breakfast at school will improve all students' grades. This conclusion:
- Is fully justified by the study's findings.
- Overlooks possible confounds and overgeneralizes the study's scope. (Correct answer)
- Is impossible to test in a school setting.
- Contradicts the study's findings.
Correct answer: Overlooks possible confounds and overgeneralizes the study's scope.
The study shows an association but does not prove that introducing breakfast will universally raise grades, especially without controlling for confounds.
Question 7: Premises: 'Either the meeting was canceled or the agenda was revised. The agenda was not revised.' What follows?
- The meeting was canceled. (Correct answer)
- The meeting happened as planned.
- Both possibilities remain open.
- The agenda may still be revised later.
Correct answer: The meeting was canceled.
In an 'either/or' statement, if one disjunct is false, the other must be true.
CCTST Inference 4
A poll shows 55% of respondents support a policy, with a margin of error of ±4%.
What can be inferred about actual public support?