use mpg in stead of mpga:
library(tidyverse)
ggplot(data = mtcars,
mapping = aes(x = cyl, y = mpg)) +
geom_col()
use mpg in stead of mpga:
library(tidyverse)
ggplot(data = mtcars,
mapping = aes(x = cyl, y = mpg)) +
geom_col()