ex.longley <- cbind(longley$Unemployed,longley$Armed.Forces)
B <- 1000
cors <- rep(0,B)
for(i in 1:B){
	ind<-sample(1:16,size=16,replace=T)
	cors[i]<-cor(ex.longley[ind,])[2,1]
}
hist(cors)
sqrt(var(cors))