TRB PG Assistant - Business statistics - introduction, sampling and sample designs, collection of primary and secondary data, measures of central tendency, measures of dispersion, simple correlation, regression analysis, chi-square test, probability One Line Questions & Answers

1. If an event is certain to occur, its probability is: — 1

2. If an event is impossible, its probability is: — 0

3. The probability of an event occurring is always between: — 0 and 1 (inclusive)

4. The correlation coefficient (r) ranges from: — -1 to 1

5. What is the sample space in probability? — The set of all possible outcomes of an experiment.

6. If the correlation coefficient is close to zero, it suggests: — A weak or non-existent linear relationship.

7. A correlation coefficient of -0.8 indicates: — A strong negative linear relationship.

8. Probability is a measure of: — The likelihood or chance that an event will occur.

9. Which of the following best describes sampling in statistics? — Selecting a subset of individuals from a larger population to make inferences about the population.

10. Regression analysis is used to: — Describe the relationship between two or more variables and predict the value of one variable based on others.

11. The Chi-Square test can be used to test for: — Both goodness of fit and independence of attributes

12. In stratified sampling, the strata should be: — Homogeneous within themselves but heterogeneous between each other.

13. A standard deviation of zero indicates: — No variability in the data; all values are the same.

14. What is the main disadvantage of census data collection compared to sampling? — It is more time-consuming and expensive.

15. Which measure of central tendency is suitable for qualitative data like 'color' or 'brand name'? — Mode

16. Which measure of central tendency is most affected by extreme values (outliers)? — Mean

17. Which measure of central tendency is calculated by summing all values and dividing by the count? — Mean

18. A correlation coefficient of +1 indicates: — A perfect positive linear relationship.

19. A sample design that ensures every member of the population has an equal and independent chance of being selected is known as: — Random sampling

20. Which method of data collection involves asking questions to respondents? — Survey

21. A questionnaire is a tool used in which data collection method? — Surveys

22. In multiple regression analysis, how many independent variables are typically involved? — More than one

23. If events A and B are mutually exclusive, then P(A ∩ B) is: — 0

24. Which of the following represents the probability of event A OR event B occurring, P(A U B)? — P(A) + P(B) - P(A ∩ B)

25. Published reports from government agencies, trade associations, and previous research studies are examples of: — Secondary data

26. Convenience sampling is a type of non-probability sampling where samples are selected based on: — Ease of access and availability.

27. Systematic sampling involves selecting elements from a population at regular intervals after a random start. What is the interval called? — Sampling interval (k)

28. Which type of data is collected directly from the source for the first time? — Primary data

29. Which sampling method involves dividing the population into homogeneous subgroups (strata) and then randomly sampling from each stratum? — Stratified Random Sampling

30. Which of the following is a non-probability sampling technique? — Quota Sampling

31. Which measure of dispersion is the average of the squared differences from the Mean? — Variance

32. Which data collection method involves direct observation of phenomena as they occur? — Observation

33. The median is preferred over the mean when the data is: — Skewed or contains outliers

34. The Chi-Square (χ²) test is primarily used for: — Testing the relationship between two categorical variables.

35. Simple correlation analysis is used to measure: — The strength and direction of the linear relationship between two variables.

36. Measures of dispersion are used to quantify: — The spread or variability of the data.

37. A scatter plot is used to visually represent: — The relationship between two quantitative variables.

38. In simple linear regression, the equation Y = a + bX represents: — The regression line, where Y is the dependent variable and X is the independent variable.

39. A key assumption for the Chi-Square test of independence is that: — The expected frequencies in each cell should not be too small (usually >5).

40. The Interquartile Range (IQR) is a measure of dispersion that represents: — The difference between the first and third quartiles.

41. The mode is the measure of central tendency that represents: — The most common value in a dataset.

42. The 'b' in the regression equation Y = a + bX represents: — The slope or the change in Y for a one-unit change in X.

43. The median of a dataset is: — The middle value when the data is ordered.

44. In probability, 'independent events' are events where: — The occurrence of one event does not affect the probability of the other.

45. Cluster sampling is most useful when: — The population is geographically dispersed and the cost of data collection is high.

46. The standard deviation is: — The square root of the variance.

47. The range of a dataset is calculated as: — The difference between the maximum and minimum values.

48. What does a negatively skewed distribution look like? — The tail on the left side is longer or stretched.

49. What is the primary goal of Business Statistics? — To make informed decisions by interpreting data.

50. Which measure of dispersion is expressed in the same units as the original data? — Standard Deviation

Business statistics - introduction, sampling and sample designs, collection of primary and secondary data, measures of central tendency, measures of dispersion, simple correlation, regression analysis, chi-square test, probability - One Line Questions