DV_Lab HW6

library(ggplot2)

## Warning: package 'ggplot2' was built under R version 4.4.3

library(dplyr)

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

ggplot(data = filter(mpg, class == "suv"),
       aes(x = reorder(manufacturer, (cty + hwy)/2, FUN = mean),
           y = (cty+hwy)/2)) +
  stat_summary(fun = "mean", geom = "col", fill = "steelblue") +
  labs(title = "1. Average Fuel Efficiency of SUVs by Manufacturer",
       x = "Manufacturer",
       y = "Average Combined MPG") 

ggplot(data = filter(mpg, class == "suv"), 
       aes(x = manufacturer, 
           y = (cty + hwy) / 2, 
           fill = factor(year, levels = c("1999", "2008")))) +
  stat_summary(fun = "mean", geom = "col", position = "dodge") +
  labs(title = "2. SUV Manufacturer Improved Fuel Economy",
       x = "Manufacturer",
       y = "Average Combined MPG",
       fill = "Year")