Chapter 3 Describing Variables

Learning objectives:

  • Review variable types
  • Explore observed distributions
  • Use summary statistics
  • Introduce theoretical distributions
sessionInfo()
## R version 4.6.1 (2026-06-24)
## Platform: x86_64-pc-linux-gnu
## Running under: Ubuntu 24.04.4 LTS
## 
## Matrix products: default
## BLAS:   /usr/lib/x86_64-linux-gnu/openblas-pthread/libblas.so.3 
## LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/libopenblasp-r0.3.26.so;  LAPACK version 3.12.0
## 
## locale:
##  [1] LC_CTYPE=C.UTF-8       LC_NUMERIC=C           LC_TIME=C.UTF-8       
##  [4] LC_COLLATE=C.UTF-8     LC_MONETARY=C.UTF-8    LC_MESSAGES=C.UTF-8   
##  [7] LC_PAPER=C.UTF-8       LC_NAME=C              LC_ADDRESS=C          
## [10] LC_TELEPHONE=C         LC_MEASUREMENT=C.UTF-8 LC_IDENTIFICATION=C   
## 
## time zone: UTC
## tzcode source: system (glibc)
## 
## attached base packages:
## [1] stats     graphics  grDevices utils     datasets  methods   base     
## 
## other attached packages:
## [1] scales_1.4.0  janitor_2.2.1 infer_1.1.0   gt_1.3.0      ggplot2_4.0.3
## [6] dplyr_1.2.1  
## 
## loaded via a namespace (and not attached):
##  [1] gtable_0.3.6       jsonlite_2.0.0     compiler_4.6.1     tidyselect_1.2.1  
##  [5] stringr_1.6.0      xml2_1.6.0         snakecase_0.11.1   jquerylib_0.1.4   
##  [9] yaml_2.3.12        fastmap_1.2.0      R6_2.6.1           generics_0.1.4    
## [13] knitr_1.51         tibble_3.3.1       bookdown_0.47      lubridate_1.9.5   
## [17] bslib_0.12.0       pillar_1.11.1      RColorBrewer_1.1-3 rlang_1.3.0       
## [21] stringi_1.8.9      cachem_1.1.0       xfun_0.60          fs_2.1.0          
## [25] sass_0.4.10        S7_0.2.2           otel_0.2.0         timechange_0.4.0  
## [29] cli_3.6.6          withr_3.0.3        magrittr_2.0.5     digest_0.6.39     
## [33] grid_4.6.1         rstudioapi_0.19.0  lifecycle_1.0.5    vctrs_0.7.3       
## [37] evaluate_1.0.5     glue_1.8.1         farver_2.1.2       purrr_1.2.2       
## [41] rmarkdown_2.31     tools_4.6.1        pkgconfig_2.0.3    htmltools_0.5.9