All Free Statistics MCQs with Answers
Every Statistics question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
545 questions · page 55 of 55
541. If the sampled population has a normal distribution, when is the sampling distribution of the sample mean X also a normal distribution ?
- A. Only when the sample size is at least 100.
- B. Only when the sample size is smaller than 30
- C. Always
- D. Only when the sample size is at least 30.
Explanation: A sample mean from a normally distributed population is normally distributed for every sample size. The sample-size rule of 30 is mainly used with non-normal populations through the central limit theorem.
Correct answer: Always542. In statistics, a sample means______________?
- A. A portion of the sample
- B. A portion of the population
- C. all the items under investigation
- D. none of the above
Explanation: A sample is a selected portion of the population used to obtain information about the whole. The entire group under investigation is called the population, not the sample.
Correct answer: A portion of the population543. Statistic is a numerical quantity, which is calculated from?
- A. Population
- B. Sample
- C. Data
- D. Observations
Explanation: A statistic is a numerical measure computed from a sample, whereas a numerical measure computed from a population is called a parameter. The sample is therefore the defining source of a statistic.
Correct answer: Sample544. When data are collected in a statistical study for only a portion or subset of all elements of interest we are using?
- A. A sample
- B. A Parameter
- C. A Population
- D. Both b and c
Explanation: When information is collected from only a portion of the elements of interest, that portion is called a sample. The complete set of elements is the population.
Correct answer: A sample545. Major area of statistics today is concerned with drawing of conclusions from__________?
- A. Samples
- B. Primary
- C. Two
- D. Complete study
Explanation: Modern statistics commonly uses sample information to draw conclusions about a larger population, which is the basis of statistical inference. Primary data and complete studies are data sources or methods, not the intended object here.
Correct answer: Samples