This exercise builds upon previous exercise. Start by redefining murder to include rate and rank:

library(dplyr)
library(dslabs)
data(murders)
murders <- mutate(murders, rate=total/population*100000, rank=rank(-rate))

Exercise

1. Suppose you want to live in a Northeast or West region and want the murder rate to be less than 1. Filter the murders dataframe with these two conditions, store your result in a dataframe my_states.

   Hint

   As always, there are multiple ways to tackle this problem:

   • Use one filter function and combine the conditions with the & operator:
     filter(dataframe, condition1 & condition2)
   • Use the filter function with a parameters for each condition. The filter function will automatically combine these conditions with an & operator:
     filter(dataframe,condition1, condition2)
   • Filter on the first conditions and filter again on the second condition:
     dataframe1 <- filter(dataframe, condition1)
dataframe2 <- filter(dataframe1, condition2)

2. Now use select on my_states to show only the state name (state) and the population size (population). Store the result in my_states_subset.