Make sure you have the library ggplot2 installed. If not, install it by running the uncommented code below: ## install. packages("ggplot2") • Run the code below to access and prepare the data: ## Load the library library(ggplot2) ## Activate the mpg data. frame provided by ggplot2 data(mpg) ## New versions of ggplot provide a tibble and have all character variables, while ## older were data frames and had factors. Transform manufacturer to factor ## to show how most data. frames treat character variables. mpg <- as. data. frame(mpg) mpg$manufacturer <- factor(mpg$manufacturer) 1. Inspect the structure of mpg data. frame. Note the kind of data provided.
2. Run the summary function to learn more about the variables.
3. Get a subset of the data. frame including all cars that are not ford nor audi.
4. Determine if the manufacturer variable (that is a factor) in your subset has or not dropped the now removed manufacurers audi and ford.
5. Devise a strategy to assure that the above factor has dropped the levels that have no elements
6. Further subset the data making sure that only front drive midsize cars model 2008 with at least 20 highway or city miles per gallon are included.
7. Determine how many cars per manufacturer satisfy these constraints. Only show manufacturers with at least one vehicle.
8. Only show the manufacturer(s) with most cars (Note: your solution should also contemplate the possibility of a tie for the first place.)