bac <-
structure(list(student = 1:16, beers = c(5L, 2L, 9L, 8L, 3L, 
7L, 3L, 5L, 3L, 5L, 4L, 6L, 5L, 7L, 1L, 4L), bac = c(0.10000000000000001, 
0.029999999999999999, 0.19, 0.12, 0.040000000000000001, 0.095000000000000001, 
0.070000000000000007, 0.059999999999999998, 0.02, 0.050000000000000003, 
0.070000000000000007, 0.10000000000000001, 0.085000000000000006, 
0.089999999999999997, 0.01, 0.050000000000000003)), row.names = c(NA, 
-16L), class = c("tbl_df", "tbl", "data.frame"))