age.group <- c(1,1,1,2,1,3,1,2,1,1,4,2,1,1,1)

gender <- c("M", "F", "M", "F", "F", "F", "M", "F", "F", "M", "M", "F", "F", "F", "F")

height.cm <- c(191.7, 166.3, 178.9, 159.3, 154.7, 167.3, 183.6, 140.8, 161.2, 188.0, 178.1, 158.0, 159.3, 150.5, 162.8)
students.data <- data.frame(gender, age.group, height.cm)

students.data