int countPositive = arr.Count(e => e > 0);
int countNegative = arr.Count(e => e < 0);
int countZero = arr.Count(e => e == 0);
string decimalPoints = "f6";

double percentPositive = (double)countPositive / n;
double percentNegative = (double)countNegative / n;
double percentZero = (double)countZero / n;

Console.WriteLine(percentPositive.ToString(decimalPoints));
Console.WriteLine(percentNegative.ToString(decimalPoints));
Console.WriteLine(percentZero.ToString(decimalPoints));