1 libreria

library(dplyr)
## 
## Adjuntando el paquete: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
url <- ('https://raw.githubusercontent.com/fhernanb/datos/master/babies.txt')

Data_14 <- read.table(url, header = TRUE, sep = '\t')

2 El box-plot

boxplot(Data_14$bwt, las=1, col="darkorchid1", horizontal = TRUE, xlab="Peso del bebe (onzas)")

boxplot(Data_14$gestation, las=1, col="red", horizontal = TRUE, xlab="Duracion del embarazo (Dias)")

boxplot(Data_14$bwt ~ Data_14$smoke, las=1)

boxplot(Data_14$bwt ~ Data_14$gestation, las=1)