This is one of the case studies from Chapter 1 of the textbook (p. 10). You may load it from the URL linked above or the resampledata package.
library(resampledata)
library(tidyverse)
glimpse(Spruce)Rows: 72
Columns: 9
$ Tree <int> 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,…
$ Competition <fct> NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, NC, C, C, C, C…
$ Fertilizer <fct> F, F, F, F, F, F, NF, NF, NF, NF, NF, NF, F, F, F, F, F, F…
$ Height0 <dbl> 15.0, 9.0, 12.0, 13.7, 12.0, 12.0, 16.8, 14.6, 16.0, 15.4,…
$ Height5 <dbl> 60.0, 45.2, 42.0, 49.5, 47.3, 56.4, 43.5, 49.2, 54.0, 45.0…
$ Diameter0 <dbl> 1.984375, 1.190625, 1.785937, 1.587500, 1.587500, 1.587500…
$ Diameter5 <dbl> 7.4, 5.2, 5.7, 6.4, 6.2, 7.4, 4.9, 5.4, 7.1, 5.1, 4.1, 7.3…
$ Ht.change <dbl> 45.0, 36.2, 30.0, 35.8, 35.3, 44.4, 26.7, 34.6, 38.0, 29.6…
$ Di.change <dbl> 5.415625, 4.009375, 3.914062, 4.812500, 4.612500, 5.812500…