Data Science and Machine Learning with R - Data Pivoting: {tidyr}

What is the primary purpose of the tidyr package?

• To perform basic arithmetic operations

• To create visualizations

• To manage databases

• To augment data manipulation capabilities

Which functions in tidyr are used to convert data between wide and long formats?

• select and mutate

• filter and arrange

• pivot_longer and pivot_wider

• gather and spread

In the context of tidyr, what does 'tidy data' mean?

• Data where each variable is in a single column

• Data with no missing values

• Data that is visually appealing

• Data stored in a database

What is the purpose of the pivot_longer function?

• To collapse data from wide to long format

• To sort data in ascending order

• To filter rows based on conditions

• To expand data from long to wide format

In the dummy data example, what was the third variable identified in the dataset?

• Grade

• Test score

• Student name

• Assessment type

What is the main advantage of converting data to a tidy format?

• It reduces the file size

• It makes data easier to manipulate and analyze

• It improves data security

• It enhances data visualization

In the Religion Income dataset, what was the third variable that needed to be collapsed?

• Year

• Income

• Religion

• Count

What is an explicit NA value in the context of the Billboard dataset?

• A missing value that is visible in the dataset

• A value that is hidden from view

• A value that is calculated from other data

• A placeholder for future data

How can you find the highest rank for each song in the Billboard dataset?

• By using the filter function

• By using the group_by and summarize functions

• By using the select function

• By using the arrange function

What is the benefit of using the group_by function in data analysis?

• It converts data to a wide format

• It removes duplicate entries

• It allows for the aggregation of data by groups

• It sorts the data alphabetically