Free Data Science MCQ Question and Answers 1 — Questions and Answers
Question 1: Which of the subsequent functions is used to calculate quantiles for numerical values?
- quantiles
- quantity
- quantile (Correct answer)
- all of the above
Correct answer: quantile
In many statistical programming languages and libraries, such as R or Python's NumPy/Pandas, the `quantile()` function is used to calculate quantiles for numerical values. Quantiles divide a dataset into equal-sized contiguous subgroups, allowing you to determine values below which a certain percentage of data falls, like the median (0.5 quantile) or quartiles.
Question 2: Which of the subsequent functions is utilized for flat file loading?
- read.table (Correct answer)
- Read.sheet
- read.data
- none of the above
Correct answer: read.table
In R, `read.table()` is a versatile and commonly used function for loading data from flat files (plain text files) into a data frame. It can handle various delimiters, specify whether a header is present, and infer data types, making it a primary tool for importing structured data from external text sources.
Question 3: How does the genetic algorithm create new states?
- Composition
- Cross-over
- Mutation
- Both Mutation & Cross-over (Correct answer)
Correct answer: Both Mutation & Cross-over
Genetic algorithms, inspired by biological evolution, create new candidate solutions (states) primarily through two operators: crossover and mutation. Crossover combines genetic material from two parent solutions to produce offspring, while mutation introduces random changes to individual solutions. These mechanisms ensure diversity in the population and enable exploration of the search space to find optimal solutions.
Question 4: Indicate which of the following is true.
- Tail function work on string
- Head function work on string
- The Head function works on the string, but the tail function does not.
- None of the above (Correct answer)
Correct answer: None of the above
The `head()` and `tail()` functions in data analysis environments (like R or Python's Pandas) are designed to display the beginning or end of data structures such as data frames, vectors, or lists. They are not typically used to operate directly on raw string literals. Therefore, none of the given statements accurately describe their functionality with respect to strings.
Question 5: The LISP processor performs the following when a top-level function is entered:
- It prints the result returned by the function (Correct answer)
- It reads the function entered
- Large memory and high-speed processor
- All of the above
Correct answer: It prints the result returned by the function
When a top-level function is entered into a LISP (or Scheme) processor, it typically operates within a Read-Eval-Print Loop (REPL). After the function is read and then evaluated, the final step in this loop is for the processor to print the result returned by that function to the console. This immediate feedback is characteristic of interactive LISP environments.
Question 6: Indicate which of the following is true.
- Questions are obtained after data processing steps
- Secondary data is the original source of data
- Primary data is the original source of data (Correct answer)
- None of the above
Correct answer: Primary data is the original source of data
Primary data refers to original, firsthand information collected directly by the researcher for the specific purpose of their study. It is gathered through methods like surveys, experiments, interviews, or direct observation. In contrast, secondary data is information that has already been collected by someone else for a different purpose.
Question 7: Which of the subsequent functions is utilized for data frame casting?
- Ucast
- Dcast (Correct answer)
- Rcast
- All of the above
Correct answer: Dcast
In R, particularly with packages like `reshape2` or `data.table`, the `dcast()` function is specifically utilized for 'casting' or reshaping data frames. It allows for the transformation of data from a 'long' format to a 'wide' format, or vice-versa, based on specified identifier and value variables, which is a common operation in data manipulation and aggregation.
Free Data Science MCQ Question and Answers 1
Which of the subsequent functions is used to calculate quantiles for numerical values?