# Obesity and McDonald's

# This is an interesting data set sho9wing the relationship between obesity rates and
# the number of McDonalds' restaurants per 100,000 population.
# Variable names are State, McDRate, and ObeseRate
#Data from http://www.csun.edu/~sg4002/research/mcdonalds_by_state.htm
# and
# http://calorielab.com/news/2010/06/28/fattest-states-2010/

data <- read.table("http://www.uvm.edu/~dhowell/methods8/DataFiles/obese.dat ", header = TRUE)
attach(data)
mod1 <- lm(ObeseRate~McDRate)
summary(mod1)
plot(ObeseRate~McDRate, main = "Obesity as Function of McDonald's/100,000")
abline(mod1)
correl <- cor(ObeseRate, McDRate)
text(6, 33, substitute (r == ".274"))

# Alternative approach when you don't know numerical value in advance
bquote(correl == .(correl))
text(3.5, 30, bquote(correl == .(correl)) )