TEST YOUR KNOWLEDGE: THE CHALLENGE OF MISSING OR DUPLICATE DATA

QUESTION 1 OF 4

Fill in the blank: Missing data has a value that is not stored for a _____ in a dataset.

visualization

column

variableCorrect Answer

row

Explanation:

Missing data has a value that is not stored for a variable in a dataset. It is typically encoded as N/A, NaN, or a blank.

QUESTION 2 OF 4

A data professional requests additional information from a dataset’s original owner. Unfortunately, they are not able to provide the information. Therefore, the data professional creates a NaN category in the dataset. What concept does this scenario describe?

Solving the problem of missing dataCorrect Answer

Mapping variables in a dataset

Managing big data

Ensuring two datasets are compatible

Explanation:

This scenario describes solving the problem of missing data. There are four common ways to do this: Request the missing values from the owner of the data; delete the missing columns, rows, or values; create a NaN category; or derive new representative values.

QUESTION 3 OF 4

When merging data, a data professional uses the following code: df_joined = df.merge(df_zip, how='left', on=['date','center_point_geom']) What is the function of the parameters how and on in this code?

To tell Python how to find missing values in the rows and columns

To tell Python how to place the appropriate values on the top row of the dataset

To tell Python which way to join the data and which column to join fromCorrect Answer

To tell Python which datasets should be merged

Explanation:

The parameters how and on tell Python which way to join the data and which column to join from. How tells Python which way to join the data, and on tells Python which column to start from.

QUESTION 4 OF 4

Non-null count is the total number of blank data entries within a data column.

True

FalseCorrect Answer

Explanation:

Non-null count is the total number of data entries for a data column that are not blank.

Ready to test your recall?

Fill in the blank: Missing data has a value that is not stored for a _____ in a dataset.

visualization

column

variable

row

How confident are you in this answer?