java - A txt file with scores(92 92 92 92 92) get assigned all A's, but with scores(92 10 70 95 84) 92 and 95 get assigned 'B'? -

so need debugging code. problem code incorrect grades assign each score in array. file reads in txt file include first name[space]last name[tab]score. stores them in arrays, calculates mean , standard deviation of scores , should assign letter grades scores, thing if rewrite txt file (92 92 92 92 92) assigned 'a' right, when txt file is(92 10 70 95 84) 92 , 95 assigned 'b' instead of 'a', problem. have spent hours trying find out why this, have had no luck. how calculate letter grades:

a = mean + standard <= score, b = mean + (standard/3) <= score < mean + standard, c = mean - (standard/3) <= score < mean + (standard/3), d = mean - standard <= score < mean - (standard/3), f = score < mean - standard

import java.io.file; import java.io.filenotfoundexception;     import java.util.scanner;  public class scannerreadfilesplit {  public static int[] scores = new int[5]; public static string[] names = new string[5]; public static char[] grades = new char[5]; public static int mean = 0; public static double standard = 0.0;  public static void main(string[] args) {       readdata();            mean = fndmean();     standard = fndstandard();      for(int x = 0; x < scores.length; x++) {       if(mean + standard <= scores[x]) {         grades[x] = 'a';        } if( (mean + (standard/3) <= scores[x]) && (scores[x] < mean + standard)) {         grades[x] = 'b';        } if( (mean - (standard/3) <= scores[x]) && (scores[x] < mean+(standard/3))) {         grades[x] = 'c';        } if( (mean - standard <= scores[x]) && (scores[x] < mean - (standard/3))) {         grades[x] = 'd';        }       if(scores[x] < mean - standard) {         grades[x] = 'f';       }     }      system.out.printf("%-22s%-22s%-22s\n", "names", "scores", "grade");         for(int k=0; k<5; k++) {             system.out.printf("%-22s%-22d%-22c\n", names[k], scores[k], grades[k]);            }            system.out.println(); }     //method called readdata() reads input file , stores names   //in array called names , scores in array called scores. * each names has   //to seperate line , scores have seperated tab.   public static void readdata() {      file file = new file("namesscore.txt");     int = 0;      try {       scanner scanner = new scanner(file);         while (scanner.hasnextline()) {              string line = scanner.nextline();             string [] words = line.split("\t");              names[i] = words[0];             scores[i] = integer.parseint(words[1]);             i++;           }          } catch (filenotfoundexception e) {           e.printstacktrace();           system.exit(0);       }   }    //method called fndmean() goes through scores array, adds elements   //and divides sum number of elements, stores value   //in variable mean1 returns value.   public static int fndmean() {         int mean1 = 0;         int sum = 0;         for(int j = 0; j < scores.length; j++) {             sum += scores[j];         }         mean1 = (sum/(scores.length));         system.out.printf("the mean of scores is: %d\n", mean1);         return mean1;     }    //method called fndstandard() finds standard deviation of scores using   //the following formula. value stores in variable standarddeviation1   //returns value    public static double fndstandard() {          double sd = 0;          for(int = 0; < scores.length; i++) {              sd += ((scores[i] - mean) * (scores[i] - mean)) / (scores.length - 1);          }          double standarddeviation1 = math.sqrt(sd);          system.out.printf("the standard deviation is: %.2f\n", standarddeviation1);          return standarddeviation1;     }   } 

for second case, have mean of 52.2 , std of ~40. 92, (mean + (standard/3) <= scores[x]) && (scores[x] < mean + standard))computes 52.2+40/3<92 , 92<52.2+40 assigned b, looks correct.