In R, which package is commonly used for working with hierarchical and mixed-effects models?

What is the purpose of the data.table package in R, particularly in comparison to the base R data frames?

A. Enhances data manipulation and provides fast operations

B. Facilitates spatial data analysis

C. Focuses on machine learning and predictive modeling

D. Performs statistical hypothesis testing

In R, what does the Rcpp package primarily enable?

A. Integration of R with C++ for improved performance

B. Data visualization and plotting

C. Natural language processing (NLP)

D. Spatial data analysis

What is the primary functionality of the shinytest package in the context of Shiny applications?

A. Automated testing of Shiny applications

B. Web scraping and data extraction

C. Time series analysis and forecasting

D. Creating and modifying network graphs

In R, which package provides tools for working with parallel computing, especially for loops?

A. foreach

B. parallelR

C. multicore

D. parallelCompute