3.8.1

ggplot(data = mpg, mapping = aes(x = cty, y = hwy)) + 
      geom_point(position = "jitter")

ggplot(data = mpg, mapping = aes(cty, hwy)) +
      geom_jitter()

ggplot(data = mpg, mapping = aes(cty, hwy)) +
      geom_count()

ggplot(data = mpg) +
      geom_boxplot(mapping = aes(x = class, y = cty))