RRB NTPC - Elementary Statistics Question Bank with Options

1. If all outcomes in a sample space are equally likely, the probability of an event is calculated as:

A) Number of favorable outcomes / Total number of outcomes

B) Total number of outcomes / Number of favorable outcomes

C) Number of unfavorable outcomes / Total number of outcomes

D) Number of favorable outcomes * Total number of outcomes

2. The probability of an event occurring is a value between:

A) 0 and 1 (inclusive)

B) 0 and 100 (inclusive)

C) -1 and 1 (inclusive)

D) 0 and infinity

3. When dealing with ordinal data (data that can be ranked but not precisely measured), which measure of central tendency is most appropriate?

A) Mean

B) Median

C) Mode

D) Standard Deviation

4. Which statistical measure is used to summarize a dataset by a single value that best represents the center of the data?

A) Measures of Dispersion

B) Measures of Central Tendency

C) Measures of Skewness

D) Measures of Kurtosis

5. In a frequency table, the 'frequency' column indicates:

A) The sum of the values

B) The number of times a particular value or range of values appears

C) The average value

D) The highest value

6. A dataset shows that 60% of the observations are below a certain value. This value represents the:

A) Mean

B) Median

C) 60th percentile

D) Mode

7. What is the interquartile range (IQR) of the dataset: 1, 3, 5, 7, 9, 11, 13?

A) 4

B) 6

C) 8

D) 10

8. What is the third quartile (Q3) of the dataset: 1, 3, 5, 7, 9, 11, 13?

A) 3

B) 5

C) 9

D) 11

9. What is the first quartile (Q1) of the dataset: 1, 3, 5, 7, 9, 11, 13?

A) 3

B) 5

C) 7

D) 9

10. If a dataset is {1, 2, 2, 3, 4, 4, 4, 5}, what is the mode?

A) 2

B) 3

C) 4

D) 5

11. If a dataset is {1, 2, 3, 4, 5}, what is the median?

A) 1

B) 2

C) 3

D) 4

12. What is the standard deviation of the dataset: 2, 4, 6, 8?

A) 2.5

B) 5

C) 6.25

D) 2.5

13. What is the variance of the dataset: 2, 4, 6, 8?

A) 2.5

B) 5

C) 6.25

D) 10

14. Calculate the range of the dataset: 15, 8, 22, 10, 18.

A) 10

B) 14

C) 22

D) 30

15. What is the mean of the dataset: 10, 20, 30, 40, 50?

A) 20

B) 30

C) 40

D) 50

16. What is the mode of the dataset: 3, 5, 3, 7, 5, 3, 8?

A) 3

B) 5

C) 7

D) 8

17. What is the median of the dataset: 2, 5, 1, 8, 3?

A) 3

B) 4

C) 5

D) 2

18. Which of the following is NOT a measure of dispersion?

A) Range

B) Variance

C) Mean

D) Standard Deviation

19. Which of the following is NOT a measure of central tendency?

A) Mean

B) Median

C) Mode

D) Standard Deviation

20. The entire group of individuals or items that we are interested in studying is called the:

A) Sample

B) Variable

C) Population

D) Statistic

21. A sample is:

A) The entire group being studied

B) A subset of the population

C) A type of statistical graph

D) A measure of central tendency

22. Which statistical concept deals with collecting, organizing, analyzing, and interpreting data?

A) Algebra

B) Geometry

C) Calculus

D) Statistics

23. In a negatively skewed distribution, the tail is longer on the:

A) Right side

B) Left side

C) Both sides

D) Top side

24. If the tail of a distribution is longer on the right side, the distribution is said to be:

A) Symmetric

B) Positively skewed

C) Negatively skewed

D) Uniform

25. A dataset where the mean, median, and mode are approximately equal is considered:

A) Skewed

B) Symmetric

C) Bimodal

D) Outlier-prone

26. What is the purpose of calculating standard deviation?

A) To find the average value

B) To determine the most frequent value

C) To measure the typical deviation of data points from the mean

D) To find the middle value of the dataset

27. The third quartile (Q3) is also known as the:

A) Median

B) 25th percentile

C) 50th percentile

D) 75th percentile

28. The first quartile (Q1) is also known as the:

A) Median

B) 25th percentile

C) 50th percentile

D) 75th percentile

29. Quartiles divide a dataset into how many equal parts?

A) Two

B) Three

C) Four

D) Ten

30. The interquartile range (IQR) is the difference between:

A) The maximum and minimum values

B) The third quartile (Q3) and the first quartile (Q1)

C) The median and the first quartile (Q1)

D) The median and the third quartile (Q3)

31. Which measure of central tendency is most affected by outliers?

A) Median

B) Mode

C) Mean

D) Interquartile Range

32. If a dataset has no repeating values, what can be said about its mode?

A) The mode is the average of all values.

B) The mode is undefined or all values are modes.

C) The mode is the smallest value.

D) The mode is the largest value.

33. A dataset with two modes is called:

A) Unimodal

B) Bimodal

C) Multimodal

D) Trimodal

34. Quantitative data represents amounts that can be measured numerically. Which of the following is an example of quantitative data?

A) Gender

B) Marital Status

C) Age

D) Nationality

35. Qualitative data describes qualities or characteristics that cannot be measured numerically. Which of the following is an example of qualitative data?

A) Height

B) Temperature

C) Color

D) Weight

36. In statistics, 'data' refers to:

A) Only numerical values

B) Facts and figures collected for analysis

C) Conclusions drawn from an experiment

D) The methods used for analysis

37. What is the purpose of a scatter plot?

A) To show the frequency distribution of a single variable

B) To compare multiple datasets

C) To visualize the relationship between two numerical variables

D) To represent parts of a whole

38. Which type of graph uses bars to represent the frequency of data points falling within specific intervals?

A) Line Graph

B) Bar Chart

C) Histogram

D) Scatter Plot

39. A pie chart is best used to represent:

A) Trends over time

B) Comparisons between different groups

C) Proportions of a whole

D) The distribution of a single variable

40. What does a histogram graphically represent?

A) A line graph of data over time

B) A bar chart showing frequencies of continuous data

C) A pie chart showing proportions

D) A scatter plot showing relationships

41. A frequency distribution table shows:

A) The order of observations

B) The number of times each value or range of values occurs

C) The average of the dataset

D) The spread of the dataset

42. The range of a dataset is defined as:

A) The sum of the highest and lowest values

B) The difference between the highest and lowest values

C) The average of the highest and lowest values

D) The number of unique values

43. Which of the following is a measure of dispersion?

A) Mean

B) Median

C) Mode

D) Range

44. The square root of the variance is called the:

A) Range

B) Interquartile Range

C) Standard Deviation

D) Mean Absolute Deviation

45. Variance is calculated as the average of the:

A) Absolute deviations from the mean

B) Squared deviations from the mean

C) Deviations from the median

D) Deviations from the mode

46. Which measure indicates the spread or dispersion of a dataset?

A) Mean

B) Median

C) Mode

D) Variance

47. The mode of a dataset is the value that:

A) Appears most often

B) Is the middle value

C) Is the average of all values

D) Represents the difference between the highest and lowest values

48. In a dataset, the median is the value that:

A) Occurs most frequently

B) Divides the dataset into two equal halves when arranged in order

C) Is the average of the first and last values

D) Represents the total sum of all values

49. The sum of all observations divided by the number of observations is known as the:

A) Median

B) Mode

C) Mean

D) Range

50. Which measure represents the central tendency of a dataset?

A) Range

B) Variance

C) Mean

D) Standard Deviation

Elementary Statistics - Question Bank