void setup() {
  float[] numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
  print(rms(numbers));
}

float rms(float[] nums) {
  float mean = 0;
  for (float n : nums) {
    mean += sq(n);
  }
  mean = sqrt(mean / nums.length);
  return mean;
}