# Multiple Choice Questions for Data Science Practice Exams

## MCQ Questions - Statistics , Graphs, Time-Series, Probability

1. Any numerical value calculated from sample data is called?

• Statistic (correct)
• Error
• Bias
• Mean

2. Variables whose measurement is done in terms such as weight, height and length are classified as?

• Continuous variables (correct)
• Measuring variables
• Flowchart variables
• Discrete variables

3. Time series is a univariate analysis.

• TRUE (correct)
• FALSE
• Can't Say
• None of the above

4. It is assumed that the number of claims arriving at an insurance company per working day has a mean of 40 and a standard deviation of 12. A survey was conducted over 50 working days. Find the probability that the sample mean number of claims arriving per working day was less than 35.

• 0.38% (correct)
• 0.16%
• 0.22%
• 0.42%

5. Exploratory data analysis is a?

• Especially appropriate for nominal data.
• Of limited value because no formal statistical tests are made.
• A set of statistical methods specially designed for exploring a small, unruly data set and identifying any abnormalities in distribution or highly unusual scores. (correct)
• The stage at which the data are described by the traditional measures of central tendency, spread and distribution shape

6. Which of the following test use in time series analysis for transformation?

• Box-Cox (correct)
• T test
• KPSS

7. Which of the following options help in adding context and interactivity to a visualization?

• Highlight
• Filter
• Parameters
• URL actions (correct)

8. 2nd Quartile = 5th Decile = 50th Percentile = ?

• Geometric Mean
• Median (correct)
• Mean
• Mode

9. Discrete attribute is

• A variable taking all the values between 0 and infinity
• A variable taking all possible values in a certain range
• A variable taking particular values (correct)
• None of above

10. For a normal distribution

• Mean < Median < Mode
• Mean = Median = Mode (correct)
• Mean > Median < Mode
• None of the above.

11. A manager is trying to predict if his reportee would leave the organization soon or not and is marking as Yes / No against their name based on his algorithms output. This churn variable which measures Yes / No can best be described as ?

• Binary
• Continuous
• Discrete (correct)
• None of the above

11. Which of the following is not a Best Practice for effective Dashboards

• Hide sheets as you go
• Limit interactivity to discourage exploration (correct)
• Know your purpose and audience
• Author at your final display size

12. What is the standard deviation of these numbers: 1,2,3,4,5,6 ?

• 3.5
• 1.87
• 2.692
• 1.71 (correct)

13. Which of the following is an assumption of time series analysis?

• Data should be stationary
• Error are normally distributed
• Data should be time related
• All of the above  (correct)

14. Skewness of normal distribution is ?

• Negative
• Positive
• 0 (correct)
• Undefined

15. The value of mode for a standard normal distribution is

• 2
• 1
• 0
• Not Fixed (correct)

16. Linear trend of time series indicates toward

• Constant rate of change
• Constant rate of growth (correct)
• Change in geometric progression
• All of the above

17. A sample can be defined as

• At least 50% of population
• Subset of a population representative of the population of interest. (correct)
• Criterion to define for the eligibility of research.
• Population of interest

18. A woman having diabetes visits the hospital and the doctor tells her that she is not diabetic. Which type of error is this?

• Both A & B
• Type II error
• No Error
• Type I error (correct)

19. Standard deviation can be negative?

• YES (correct)
• NO
• Can't say

20. Skewness of normal distribution is ?

• Negative
• Positive
• 0 (correct)
• Undefined

21. A card is drawn at random from an ordinary pack of 52 playing cards. What is the probability that it is a king; given that it is a face card? [a face card is either a jack, a queen or a king].

• 1/4
• 1/13
• 1/3 (correct)
• 1/12

22. Which of the following aspects of Tableau isn't one of the many factors that affect overall performance?

• Coloring (correct)
• Query execution
• Geocoding
• Connections to data sources

23. ___________ is a dimension or measure that narrows the data shown in a view to focus on relevant information.

• Filter
• Group
• Set
• Parameter (correct)

24. The value of mode for a standard normal distribution is

• 2
• 1
• 0
• Not Fixed (correct)

25. The sampling in which each object in the population has equal chance of being selected is

• Random Sampling (correct)
• Stratified sampling
• Cluster sampling
• Convenience sampling

26. Which of the following is not a component of time series analysis

• Seasonal
• Trend
• Random
• None of the above (correct)

27. The point where null hypothesis gets rejected is called as ?

• Acceptance value
• Significant value
• Rejection value
• Critical  (correct)

28. Which of the following chart types is not a way to show relationship between numerical values?

• Histogram
• Tree Maps
• Cross-Tab (correct)
• Scatter Plots

29. Which of the following layers are not readily available in Tableau Maps?

• State/Province Borders
• County Names
• Coastline (correct)
• Airports

30. Spinning plots can be use for two dimensional data

• FALSE
• TRUE (correct)
• Can't Say
• None of the above

31. Which of the following is an invalid Join in Tableau?

• Union
• Inner Join
• Subset Join (correct)
• Outer Join

32. Which of the following belongs to the central of tendency?

• Mean
• Median
• Mode
• All of the above (correct)

33. A statement made about a population for testing purposes is called?

• Statistic
• Test-statistic
• Level of Significance
• Hypothesis (correct)

34. Which one of the following is the benefit of using simple random sampling ?

• Informants can refuse to participate
• The results are always representative
• We can calculate the accuracy of results (correct)
• Interviewers can choose respondents freely

35. In a lottery, there are 8 prizes and 24 blanks. A lottery is drawn at random. What is the probability of getting a prize

• 1/4 (correct)
• 1/3
• 1/8
• 1/24

36. Which one of the following is the main problem with using non-probability sampling techniques?

• The results are never representative
• Human judgement error (correct)
• The expense
• Informants can refuse to participate

37. Parameter of Holt-Winter method of time series analysis Alpha, Beta and Gamma represent the Level, Trend and Season component respectively.

• FALSE
• TRUE (correct)
• Can't Say
• None of the above

38. Which of the following visualization technique use for proportion?

• Bar chart
• Line chart
• Histogram
• Pi chart (correct)

39. The sampling in which each object in the population has equal chance of being selected is

• Random Sampling (correct)
• Stratified sampling
• Cluster sampling
• Convenience sampling

40. You are in a mall and a person approaches you asks you to participate in an ongoing study on use of mobile phones. Which type of sampling is this?

• Stratified sampling
• Cluster sampling
• Convenience sampling (correct)
• Random sampling

41. Which one of these sampling sources will be the most incomplete for a sample of nationally representative households?

• The postcode address file (PAF)
• The electoral register
• A customer database (correct)
• Telephone directories

42. In sampling with replacement a sampling unit can be selected

• None of above
• More than one time (correct)
• Less than one time
• Only once

43. The arithmetic mean of a set of 10 numbers is 20. If each number is first multiplied by 2 and then increased by 5, then what is the mean of new numbers?

• 20
• 25 (correct)
• 40
• 45