Biostatistics: practice question

A PSM question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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PSM · Biostatistics

Sample item

A study finds a correlation coefficient of -0.9 between two quantitative variables. What does this indicate?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. A strong inverse linear relationship

The correlation coefficient ranges from -1 to +1. A value near -1 shows a strong negative linear relationship, but correlation alone does not prove causation.

Option by option

  • A. A weak inverse linear relationship

    A value of -0.9 lies close to the extreme of -1, so the relationship is strong rather than weak.

  • B. No linear relationship

    No linear relationship corresponds to a value near zero.

  • C. A strong inverse linear relationship (correct)

    Values near -1 show that one variable tends to fall as the other rises.

  • D. That one variable causes the other to fall

    Correlation does not establish causation, however strong.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More PSM questions

Questions about this PSM question

What is the answer to this PSM question?

The best answer is C, A strong inverse linear relationship. The correlation coefficient ranges from -1 to +1.

Why is "A weak inverse linear relationship" not the answer?

A value of -0.9 lies close to the extreme of -1, so the relationship is strong rather than weak.

Why is "No linear relationship" not the answer?

No linear relationship corresponds to a value near zero.

Why is "That one variable causes the other to fall" not the answer?

Correlation does not establish causation, however strong.

What concept does this question test?

It tests Biostatistics in PSM. A value near -1 shows a strong negative linear relationship, but correlation alone does not prove causation.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Biostatistics?

Practise biostatistics with small calculations until sensitivity, predictive values and risk measures are automatic. Then use the flashcards and the other PSM questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.