Test: Collection of Data - 2 - Commerce MCQ

When data is collected from the entire population it is called Census method. It includes total count. By this method, more reliable data can be obtained since every item of the whole population is included. The merits of Census method include:
(a) It is accurate.
(b) It rules out errors of sampling since very item of the population is included.
(c) It is reliable

- Sampling can lead to errors due to:
- Sampling Bias: Non-representative samples that skew results.
- Sampling Error: Natural variation when only part of a population is studied.
- While sampling is generally cost-effective and faster than a full census, it is not free from errors.
- Option A is incorrect because sampling is typically less expensive and quicker than surveying an entire population.
- Therefore, the correct answer is B, as it highlights that sampling is subject to errors.

When the investigator himself does not make any investigation and rather uses the data which has been collected by some other researcher such data is known as secondary data. The sources of collecting secondary data are:
(i) published sources like newspapers, articles, blogs, etc.
(ii) unpublished sources like unpublished news, etc.
Hence, the correct answer is option D.

Stratified sampling is a type of sampling method in which the total population is divided into smaller groups or strata to complete the sampling process. The strata is formed based on some common characteristics in the population data. After dividing the population into strata, the researcher randomly selects the sample proportionally. Hence, correct answer is option B.

Census method is the method of statistical enumeration where all members of the population are studied. A population refers to the set of all observations under concern. In our country, the Government conducts the Census of India every ten years. This method must take into account all the units. It cannot leave out anyone in collecting data. Once collected, the Census of India reveals demographic information such as birth rates, death rates, total population, population growth rate of our country, etc. The last census was conducted in the year 2011. Hence, correct answer is option C.

- A sample is a subset of a population, not the entire population.
- Options B and C specify specific percentages, but a sample can be any size.
- Option D is incorrect because it refers to the entire population, not a sample.
- Option A is correct because a sample consists of some units, selected from the population, and used to represent the whole.
- Sampling allows for analysis and conclusions about the entire population without examining every individual unit.

- A parameter is a numerical characteristic of a population. It represents the entire group being studied.
- A statistic is a numerical characteristic of a sample. It is derived from a subset of the population.
- Therefore, a parameter and a statistic are characteristics of a population and a sample, respectively.
- Correct answer: A: Population and sample.

  - A sample refers to a subset of items taken from a larger population or universe. It is used to represent the entire group in research or statistical analysis.
- By analyzing the sample, conclusions can be drawn about the whole population without needing to examine every individual item.
- This approach is efficient and practical, especially when dealing with large populations, making "Sample" the correct answer.

Secondary data is the second-hand information as it is not collected by the user. Thus, secondary data refers to the data which is already collected and published by other authorities. For example, government census report is a secondary data. Hence, correct answer is option B.

Population or the Universe in statistics means totality of the items under study. Thus, the Population or the Universe is a group to which the results of the study are intended to apply. Hence, correct answer is option C.