A researcher wants the average daily reading time of a city's students. Which sample is most likely to be biased?

Students picked by lottery from all school rollsCorrect answerYour answerEvery 50th student on a combined list of the city's studentsCorrect answerYour answerA random sample from each school, in proportion to its sizeCorrect answerYour answerStudents found in the city library on one afternoonCorrect answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer D

Correct answer: D

A biased sample systematically over- or under-represents part of the population.
Students in a library are likely to read more than average, so that sample overstates reading time.

Concept: Representative and biased samples
Typical timeTypical: 90 s
Your timeYours: —

The rule this testsPopulation and sample

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Ten questions from Sampling, Inference & the t-Test, at your own pace.

A researcher wants the average daily reading time of a city's students. Which sample is most likely to be biased?

Explanation