podaci = nerv$V1
n = length(podaci)

koef_asimetrije = function(x) {
  sqrt(length(x)) * sum((x - mean(x))^3) / (sum((x - mean(x))^2))^(3 / 2)
}

(Tn = koef_asimetrije(podaci))

Tn_i = rep(0, n)
for (i in 1:n) {
  Tn_i[i] = koef_asimetrije(podaci[-i])
}

(Tn_. = mean(Tn_i))

(se_jack = sqrt((n - 1) / n * sum( (Tn_i - Tn_.)^2 )))