exercise.R

# Exercise 2: Data Frame Practice with `dplyr`.
# Use a different appraoch to accomplish the same tasks as exercise-1

# Install devtools package: allows installations from GitHub
install.packages('devtools')

# Install "fueleconomy" package from GitHub
devtools::install_github("hadley/fueleconomy")

# Require/library the fueleconomy package


# You should have have access to the `vehicles` data.frame


# Create a data.frame of vehicles from 1997


# Use the `unique` function to verify that there is only 1 value in the `year` column of your new data.frame


# Create a data.frame of 2-Wheel Drive vehicles that get more than 20 miles/gallon in the city


# Of those vehicles, what is the vehicle ID of the vehicle with the worst hwy mpg?


# Write a function that takes a `year` and a `make` as parameters, and returns 
# The vehicle that gets the most hwy miles/gallon of vehicles of that make in that year


# What was the most efficient honda model of 1995?