CompTIA Data+ (DA0-001) — Question 128

Which of the following best describes the law of large numbers?

Answer options

• A. As a sample size decreases, its standard deviation gets closer to the average of the whole population.
• B. As a sample size grows, its mean gets closer to the average of the whole population.
• C. As a sample size decreases, its mean gets closer to the average of the whole population.
• D. When a sample size doubles, the sample is indicative of the whole population.

Correct answer: B

Explanation

The law of large numbers states that as the size of a sample increases, the sample mean will tend to get closer to the population mean, making option B the correct answer. Options A and C incorrectly relate sample size to standard deviation and mean, respectively, in the wrong context. Option D misrepresents the relationship between sample size and representativeness.