double media (double *p, int elementos){

    int i;
    double sumatorio=0.0, media=0.0;

    for (i = 0; i < elementos; i++){
        sumatorio = sumatorio + *p;
        p++;
    }

    media = sumatorio / elementos;

    return(media);
}

double varianza(double *p, int n){
    int i;
    double med=0, var=0;

    med=media(*p,n);
    for (i = 0; i < n; i++){
            var = var + (*p - med)*(*p - med);
            p++;
    }
    var = var/(n-1);
    return (var)
}