#uticajna kriva disperzije
Y<-rnorm(30,1,30)
X<-seq(-10,10,0.1)
N<-length(X)
NY<-length(Y)
Yn<-0
Nt<-NY+1
for(i in 1:N){
  Xt<-X[i]
  Y[Nt]<-Xt
  A<-(Xt-mean(Y))^2-mean(Y-mean(Y))^2
  Yn[i]<-A
}
plot(X,Yn)