#Exercice 2

setwd("C:/Documents and Settings/A276/Bureau")
pop <- read.table("pop_eu.txt")

#1.
Population <- pop$V2
Annees <- pop$V1
plot(Annees,Population)

#2.
cor.test(Annees,Population,method="pearson")

#3.
reg <- lm(Population~Annees)
a <- reg$coefficients[1]
b <- reg$coefficients[2]
abline(a,b)

#4.
nv <- data.frame(V1=c(2010))
nv2 <- b*nv+a
predict(reg,newdata=nv)
conf <- predict(reg,newdata=nv,interval="confidence")lines(c(2010,2010),c(conf[2],conf[3]),col="green")
pred <- predict(reg,newdata=nv,interval="prediction")lines(c(2010,2010),c(pred[2],pred[3]),col="orange")

#5.
plot(Annees,sqrt(Population))

#6.
reg <- lm(sqrt(Population)~Annees)
a1 <- reg$coefficients[1]
b1 <- reg$coefficients[2]
abline(a1,b1)

#8.

