Code for Overview and Descriptive Statistics

• utils.R (utilities for this section of the book)
  
• ex1_02.R (code for this section of the book)
  
• ex1_03.R (code for this section of the book)
  
• ex1_04.R (code for this section of the book)
  
• ex1_supplementary_exercises.R (code for this section of the book)