"chickwts" <-
structure(list(weight = c(179, 160, 136, 227, 217, 168, 108, 124, 143, 
140, 309, 229, 181, 141, 260, 203, 148, 169, 213, 257, 244, 271, 243, 230, 
248, 327, 329, 250, 193, 271, 316, 267, 199, 171, 158, 248, 423, 340, 392, 
339, 341, 226, 320, 295, 334, 322, 297, 318, 325, 257, 303, 315, 380, 153, 
263, 242, 206, 344, 258, 368, 390, 379, 260, 404, 318, 352, 359, 216, 222, 
283, 332), feed = structure(factor(c(2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 
6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1), levels=1:6), .Label = c("casein",
"horsebean", "linseed", "meatmeal", "soybean", "sunflower"))),
row.names = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11",
"12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23",
"24", "25", "26", "27", "28", "29", "30", "31", "32", "33", "34", "35",
"36", "37", "38", "39", "40", "41", "42", "43", "44", "45", "46", "47",
"48", "49", "50", "51", "52", "53", "54", "55", "56", "57", "58", "59",
"60", "61", "62", "63", "64", "65", "66", "67", "68", "69", "70", "71"),
class = "data.frame")