install.packages("gapminder")

library(gapminder)
library(dplyr)
library(ggplot2)
aggregate(lifeExp ~ continent, gapminder, median)
#>   continent lifeExp
#> 1    Africa 47.7920
#> 2  Americas 67.0480
#> 3      Asia 61.7915
#> 4    Europe 72.2410
#> 5   Oceania 73.6650
gapminder %>%
  filter(year == 2007) %>%
  group_by(continent) %>%
  summarise(lifeExp = median(lifeExp))
#> # A tibble: 5 × 2
#>   continent lifeExp
#>   <fct>       <dbl>
#> 1 Africa       52.9
#> 2 Americas     72.9
#> 3 Asia         72.4
#> 4 Europe       78.6
#> 5 Oceania      80.7
ggplot(gapminder, aes(x = continent, y = lifeExp)) +
  geom_boxplot(outlier.colour = "hotpink") +
  geom_jitter(position = position_jitter(width = 0.1, height = 0), alpha = 1 / 4)