knitr::opts_chunk$set(echo = FALSE)


data(trees)
Arboles <- trees[trees$Height >= 70 & trees$Height <= 80 & trees$Girth < 13, ]
plot(trees$Girth, trees$Height, 
     main = "Altura y Ancho de Árboles Cherry Negros",
     xlab = "Diámetro (pulgadas)", 
     ylab = "Altura (pies)", 
     col = ifelse(trees$Height >= 70 & trees$Height <= 80 & trees$Girth < 13, "green", "black"),
     pch = 15)
legend("topleft", legend = "Diámetro vs Altura", pch = 15, col = c("green", "black"))