Data Cleansing MCQ's

1. Data munging is

   View Answer   

   A Process to clean messy data

2. Can a technically correct dataset still be incorrect for data analysis?

a) YES
b) NO
   View Answer   

   YES

3. Binning is a method to manage data

   View Answer   

   noisy data

4. Data cleaning is the most time consuming process in data analysis

a) True
b) False
   View Answer   

   True

5. tail() function shows ___ by default

   View Answer   

   6 rows

6. ____ can be used to view data distribution of a single variable AND ____ can be used to view relation between 2 variables

   View Answer   

   hist(),plot()

7. Consider cars built-in R dataset and find out what is the median of dist variable

   View Answer   

   36

8. Using head function, identify the 8th row of mtcars built-in dataset

   View Answer   

   10 26

9. In a tidy data set ___ forms a row and ____ forms a column

   View Answer   

   Observation,Variable

10. Identify the function which is part of dplyr package that helps in previewing the data.

   View Answer   

   glimpse()

11. A dataset with columns (country, disease, #ofdeaths) has values Row1 - (CONGO, TB, 28) Row2 - (SPAIN, TB, 2) Row3 - (EGYPT, TB, 0). Is this is a tidy or messy dataset.?

   View Answer   

   Tidy Data

12. filter() is for selecting columns and select() is for selecting rows

a) True
b) False
   View Answer   

   False

13. ___ allows to make new variables

   View Answer   

   mutate()

14. Which function(s) of dplyr would you use to first subset the columns and then sort them on a particular column?

   View Answer   

   filter(),arrange()

15. What is the class of sys.date() and sys.time()

   View Answer   

   POSIXct

16. Can a variable of factor type be converted to a date type

   View Answer   

   No

17. If value of time is system time which is 2016-12-21 18:33:31 UTC. What is the output for time+60

   View Answer   

   0.773611111111111

18. What are the possible outlier treatment

   View Answer   

   all the options

19. Identify the correct ones

   View Answer   

   separate() makes

20. ____ is similar to separate() function

   View Answer   

   extract()

21. Which one is NOT a special value in R

   View Answer   

   None of the options

22. ____ can be used to identify the existence of a matching pattern in a string

   View Answer   

   str.detect()

23. 

   View Answer   

   

24. print() is the recommended function to view the dataset

   View Answer   

   No,Not....