1. What is Data Science?
A) An interdisciplinary field that extracts knowledge from data
B) A programming language for databases
C) A type of computer hardware
D) A statistical software package
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2. Which of the following is NOT a typical step in the Data Science process?
A) Data Collection
B) Data Cleaning
C) Hardware Installation
D) Model Validation
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3. What type of Data Science question asks 'What happened?'
A) Predictive
B) Descriptive
C) Prescriptive
D) Causal
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4. What is the primary purpose of experimental design in Data Science?
A) To collect more data
B) To clean existing data
C) To visualize data patterns
D) To test hypotheses systematically
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5. What is R primarily used for?
A) Statistical computing and graphics
B) Web development
C) Mobile app development
D) System administration
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6. What is a vector in R?
A) A two-dimensional data structure
B) A function for mathematical operations
C) A one-dimensional array of elements
D) A type of loop structure
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7. Which function is used to create a vector in R?
A) vector()
B) c()
C) create()
D) make()
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8. What is a matrix in R?
A) A two-dimensional array of the same data type
B) A one-dimensional list
C) A collection of different data types
D) A function for data manipulation
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9. What makes lists different from vectors in R?
A) Lists are faster to process
B) Lists use less memory
C) Lists are only for numeric data
D) Lists can contain different data types
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10. What are factors used for in R?
A) Mathematical calculations
B) Creating loops
C) Representing categorical data
D) File input/output operations
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11. What is a data frame in R?
A) A single column of data
B) A table-like structure with rows and columns
C) A mathematical function
D) A type of plot
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12. Which operator is used for equality comparison in R?
A) ==
B) =
C) !=
D) <>
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13. What does the & operator do in R logical statements?
A) Logical OR
B) Logical NOT
C) Logical AND
D) Assignment
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14. What is the correct syntax for an if-else statement in R?
A) if condition then action1 else action2
B) if (condition) { action1 } else { action2 }
C) if [condition] action1 else action2
D) if condition: action1 else: action2
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15. How do you define a function in R?
A) function_name <- function(parameters) { body }
B) def function_name(parameters): body
C) function function_name(parameters) { body }
D) create function_name(parameters) { body }
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16. What is the syntax for a for loop in R?
A) for variable = 1 to n { body }
B) for (variable = 1; variable <= n; variable++) { body }
C) for (variable in sequence) { body }
D) for variable in range(n): body
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17. When does a while loop stop executing in R?
A) After a fixed number of iterations
B) When the condition becomes FALSE
C) When an error occurs
D) When the user interrupts
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18. What type of Data Science question involves making inferences about a population from a sample?
A) Descriptive
B) Exploratory
C) Predictive
D) Inferential
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19. What characterizes structured data?
A) Organized in rows and columns
B) Has no predefined format
C) Contains only text data
D) Is always numerical
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20. Which of the following is an example of unstructured data?
A) Excel spreadsheet
B) SQL database table
C) Social media posts
D) CSV file
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21. Which operator is commonly used for assignment in R?
A) =
B) <-
C) :=
D) ==
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22. What does the length() function return in R?
A) Number of elements in a vector
B) Size of memory used
C) Number of characters in a string
D) Number of rows in a matrix
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23. What does the str() function do in R?
A) Converts to string
B) Calculates string length
C) Shows the structure of an object
D) Sorts elements
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24. How do you access the first element of a vector named 'x' in R?
A) x(1)
B) x{1}
C) x.1
D) x[1]
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25. What function tells you the data type of an object in R?
A) type()
B) class()
C) typeof()
D) mode()
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26. What is the goal of predictive Data Science questions?
A) To forecast future events
B) To describe current state
C) To find correlations
D) To clean data
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27. What is the purpose of a control group in experimental design?
A) To increase sample size
B) To reduce costs
C) To provide a baseline for comparison
D) To speed up the experiment
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28. What does the names() function do in R?
A) Creates new variables
B) Gets or sets names of object elements
C) Counts the number of names
D) Sorts names alphabetically
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29. Which function returns the dimensions of a matrix in R?
A) size()
B) length()
C) nrow()
D) dim()
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30. What does the is.na() function check for in R?
A) Missing values
B) Numeric values
C) Character values
D) Logical values
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31. What does the rep() function do in R?
A) Removes elements
B) Replaces elements
C) Replicates elements
D) Reverses elements
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32. Which function creates a sequence of numbers in R?
A) range()
B) seq()
C) series()
D) num()
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33. What does the paste() function do in R?
A) Copies objects
B) Pastes from clipboard
C) Creates new variables
D) Concatenates strings
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34. Which function sorts elements in R?
A) sort()
B) order()
C) arrange()
D) rank()
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35. What does the unique() function return in R?
A) All elements
B) Duplicate elements
C) Unique elements only
D) First element
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36. What does the which() function do in R?
A) Counts TRUE values
B) Returns indices of TRUE elements
C) Converts to logical
D) Finds maximum value
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37. What is the purpose of the apply() function in R?
A) To create applications
B) To install packages
C) To apply formatting
D) To apply functions to arrays
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38. Which function provides a summary of an R object?
A) summary()
B) describe()
C) info()
D) details()
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39. What does the head() function show in R?
A) Column headers only
B) Last few rows
C) First few rows
D) Random rows
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40. What does the tail() function display in R?
A) First few rows
B) Last few rows
C) Middle rows
D) All rows
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41. Which function calculates the average in R?
A) avg()
B) average()
C) median()
D) mean()
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42. What does the median() function calculate in R?
A) Middle value of sorted data
B) Most frequent value
C) Average value
D) Range of values
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43. Which function calculates variance in R?
A) variance()
B) spread()
C) var()
D) sd()
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44. What does the sd() function calculate in R?
A) Sum of deviations
B) Standard deviation
C) Standard error
D) Sum of squares
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45. What does the range() function return in R?
A) Difference between max and min
B) All values in order
C) Middle values
D) Minimum and maximum values
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46. Which function finds the maximum value in R?
A) max()
B) maximum()
C) largest()
D) top()
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47. What does the min() function return in R?
A) Minimum index
B) Smallest value
C) First value
D) Negative values
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48. Which function calculates the total sum in R?
A) total()
B) add()
C) sum()
D) plus()
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49. What does the quantile() function calculate in R?
A) Quality measures
B) Quantity of data
C) Qualitative analysis
D) Percentiles of data
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50. What does the table() function create in R?
A) Frequency tables
B) Data tables
C) HTML tables
D) Pivot tables
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