code: private boolean rule6(double sample) {
          if (!hasMean()) {
              return false;
          }
  
          if (rule6LastFive.size() == 5) {
              switch (rule6LastFive.removeLast()) {
                  case ">":
                      --rule6Above;
                      break;
                  case "<":
                      --rule6Below;
                      break;
              }
          }
  
          if (Math.abs(sample - mean.getResult()) > oneDeviation) {
              if (sample > mean.getResult()) {
                  ++rule6Above;
                  rule6LastFive.push(">");
              } else {
                  ++rule6Below;
                  rule6LastFive.push("<");
              }
          } else {
              rule6LastFive.push("");
          }
  
          return rule6Above >= 4 || rule6Below >= 4;
      }
docs: At least 4 of 5 points in a row are > 1 standard deviation from the mean in the same direction