Which of the following statements are correct?
(A) A sample size of 30 or more is considered to be sufficient to hold the central limit theorem.
(B) A survey done using a sample of the population has no margin of error.
(C) The measurable characteristic of a population is called parameter.
(D) The sample makes an inference about the population.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A), (C) and (D) only
A sample is studied to draw conclusions about the whole population. A measurable characteristic of the population is a parameter, and the matching value from the sample is a statistic.
So a sample of 30 or more is taken as large enough for the central limit theorem, every sample estimate has a margin of error, and the sample is used to infer about the population.
Checking the statements
(A) A sample size of 30 or more is considered to be sufficient to hold the central limit theorem. — Correct. n ≥ 30 is the usual rule for a large sample.
(B) A survey done using a sample of the population has no margin of error. — Incorrect. A sample does not include the whole population, so its estimates always have a margin of error.
(C) The measurable characteristic of a population is called parameter. — Correct. This is the definition of a parameter.
(D) The sample makes an inference about the population. — Correct. Sample results are used to draw conclusions about the population.