prison <-
structure(list(pre_trt1 = c(67L, 86L, 64L, 69L, 67L, 79L, 67L, 
67L, 69L, 57L, 76L, 90L, 71L, 93L), post_trt1 = c(74L, 50L, 64L, 
76L, 64L, 81L, 74L, 50L, 60L, 57L, 62L, 76L, 71L, 76L), pre_trt2 = c(88L, 
79L, 67L, 83L, 79L, 76L, 71L, 67L, 69L, 67L, 67L, 74L, 81L, 81L
), post_trt2 = c(79L, 81L, 83L, 74L, 76L, 69L, 71L, 75L, 64L, 
64L, 64L, 71L, 74L, 64L), pre_trt3 = c(86L, 53L, 81L, 69L, 81L, 
76L, 74L, 60L, 67L, 86L, 86L, 74L, 71L, 71L), post_trt3 = c(90L, 
53L, 102L, 67L, 76L, 81L, 69L, 60L, 69L, 83L, 107L, 71L, 71L, 
81L)), row.names = c(NA, -14L), class = c("tbl_df", "tbl", "data.frame"
))