Question

question about R:

The vectors state.name, state.area, and state.region are pre-loaded in R and contain US state names, area (in square miles), and region respectively.

(a) Identify the data type for state.name, state.area, and state.region.

(b) What is the longest state name (including spaces)? How long is it?

(c) Compute the average area of the states which contain the word “New” at the start of the state name. Use the function substr().

(d) Use the function table() to determine how many states are in each region. Use the function kable() to include the table in your solutions. (Notes: you will need the R package knitr to be able to use kable().

Answer 1

Data sets related to the 50 states of the United States of America.

Usage

state.abb
state.area
state.center
state.division
state.name
state.region
state.x77

Details

R currently contains the following “state” data sets. Note that all data are arranged according to alphabetical order of the state names.

state.abb:

character vector of 2-letter abbreviations for the state names.

state.area:

numeric vector of state areas (in square miles).

state.center:

list with components named x and y giving the approximate geographic center of each state in negative longitude and latitude. Alaska and Hawaii are placed just off the West Coast.

state.division:

factor giving state divisions (New England, Middle Atlantic, South Atlantic, East South Central, West South Central, East North Central, West North Central, Mountain, and Pacific).

state.name:

character vector giving the full state names.

state.region:

factor giving the region (Northeast, South, North Central, West) that each state belongs to.

state.x77:

matrix with 50 rows and 8 columns giving the following statistics in the respective columns.

Population:

population estimate as of July 1, 1975

Income:

per capita income (1974)

Illiteracy:

illiteracy (1970, percent of population)

Life Exp:

life expectancy in years (1969–71)

Murder:

murder and non-negligent manslaughter rate per 100,000 population (1976)

HS Grad:

percent high-school graduates (1970)

Frost:

mean number of days with minimum temperature below freezing (1931–1960) in capital or large city

Area:

land area in square miles